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ALSO: Genetics • Online CL Sales • CXL for Kids • Rethinking Corneal Disease • Daily Disposables • Retained PK Sutures
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contents
Review of Cornea & Contact Lenses | January/February 2017
departments
4
News Review
Evidence Supports Long-term
Efficacy of Collagen Crosslinking
6
My Perspective
features
12
Get to Know Your Genes
By Joseph P. Shovlin, OD
7
Guest Editorial
Combating Online Contact Lens
Sales
By Andrea P. Thau, OD, AOA president
8
Fitting Challenges
The Right Lens for a Corneal Scar
By Vivian P. Shibayama, OD
34
16
The GP Experts
Treating Infantile Aphakia: Think GPs
Pharma Science and Practice
Corneal Collagen Crosslinking:
Not Just for Adults
By Elyse L. Chaglasian, OD, and
Tammy Than, MS, OD
38
Corneal Consult
A New Year, A New Look at
the Cornea
By Aaron Bronner, OD
40
Practice Progress
Daily Disposables: Effective From
Allergy to Astigmatism
By Mile Brujic, OD, and
David Kading, OD
42
The Big Picture
Retained PK Sutures
By Christine W. Sindt, OD
Become a Fan on
Facebook
/ReviewofCorneaAndContactLenses
Steady growth in the prevalence of this
deceptively simple condition will expose
half the world’s population to visual
impairment. Here’s what to expect and
what we should do.
By Monica Jong, PhD, BOptom,
Padmaja Sankaridurg, PhD, BOptom,
Timothy R. Fricke, BOptom, MSc,
Thomas John Naduvilath, PhD,
Serge Resnikoff, MD, PhD, and
Kovin Naidoo, OD, PhD
CE — Fitting Multifocal
Contact Lenses for Myopia
Control
These practice
pearls aid in myopia
management,
including avoiding
onset and slowing
progression in
patients of all ages.
By Padmaja Sankaridurg, PhD, BOptom
By Robert Ensley, OD, and
Heidi Miller, OD
36
Myopia on the Move
Follow Us On
Twitter
22
26
30
10 Tips From an
Orthokeratology Expert
Don’t let misconceptions stop you from
using this treatment modality that can
provide a huge benefit to patients with
myopia.
By Cary M. Herzberg, OD
Reshaping Ortho-K
Toric Lenses can expand myopia
management to include patients with
astigmatism.
By Daddi Fadel, DOptom
Keys to a Pediatric
Soft Lens Fitting
From infancy to adolescence, contact
lenses prove a viable and beneficial
treatment option for a range of conditions.
By Erin C. Jenewein, OD, MS, and
Kriti Bhagat, OD
@RCCLmag
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
3
News Review
IN BRIEF
■ Meibomian gland damage may be reversible in patients with meibomian gland
dysfunction (MGD), a recent study in Cornea suggests.1 The key treatment used in
the study was an artificial lubricant four
times a day, coupled with eyelid hygiene
once a day. Researchers found the dual
approach resulted in a 5.4% decrease
in MG dropout in upper eyelids and a
4.6% decrease of MG dropout in lower
eyelids, as well as improvement across all
clinical indices for study participants who
heeded the instructions to take care of
eyelid hygiene.Participants who ignored
doctors’ orders did not experience the
same improvement, save for some in the
ocular surface disease index.
1. Yin Y, Gong L. Reversibility of gland dropout and
significance of eyelid hygiene treatment in meibomian
gland dysfunction. Cornea. October 14, 2016. [Epub
ahead of print].
■ The first Descemet’s membrane endothelial keratoplasty (DMEK) patient recently presented for a 10-year follow up,
and the clinical outcomes are encouraging, according to a recent report.1 The patient showed all the short- and long-term
characteristics of this endothelial keratoplasty technique, including outstanding
patient satisfaction, quick visual recovery,
low incidence of complications and graft
longevity. Best spectacle-corrected visual
acuity in both eyes remained stable from
the initial postoperative improvements.
While this case covers just one patient’s
outcome, results such as these may show
the potential for DMEK to be adopted as
the preferred treatment option for corneal endothelial disorders in the future.
1. Baydoun B, Müller T, Lavy I. Ten-year clinical outcome
of the first patient undergoing Descemet membrane
endothelial keratoplasty. Cornea. December 8, 2016.
[Epub ahead of print].
With this issue, Review of Cornea & Contact
Lenses adopts a bimonthly publishing
frequency with more content per issue, as it
expands its slate of contributors:
A new Guest Editorial column will tackle
controversies of the day, starting this month
with AOA President Andrea Thau, OD,
addressing online contact lens sales, p. 7.
Expert specialty contact lens practitioner
Vivian Shibayama, OD, explains how to
approach hard-to-fit patients in Fitting
Challenges, p. 8.
Aaron Bronner, OD, gives advice from his
unique multispecialty comanagement setting
in the Corneal Consult column, p. 38.
David Kading, OD, joins long-time RCCL
contributor Mile Brujic, OD, in coauthoring
Practice Progress, p. 40.
Associate Clinical Editor Christine Sindt, OD,
shares large-format images from her universitybased practice in The Big Picture, p. 42.
Additional enhancements will debut later this
year online at reviewofcontactlenses.com.
4
Evidence Supports Long-term
Efficacy of Collagen Crosslinking
C
orneal collagen crosslinking (CXL) may be effective in managing keratoconus for longer than two
years, according to a recent study
in the journal Cornea. A possible
reversal of CXL effects after four
years was also discovered.
The study followed 377 eyes
in pediatric patients ages eight
to 18, all of whom had progressive keratoconus and underwent
CXL. Of the eyes tracked, 194
had follow-ups more than two
years post-treatment, the results of
which show a significant improvement in mean spectacle-corrected
distance visual acuity (CDVA), a
reduction in mean topographic
astigmatism, flattening of keratometry (Kmax) and corneal thinning of 31.1 ± 36.0µm.
Despite these promising results,
the study also revealed the effects
of CXL reversed after four years
post-treatment in some eyes.
The researchers noted stabilization or flattening of Kmax in
85% of eyes at two years, which
dropped to 76% after four years.
CDVA improved in 80.1% of eyes
at two years, but only in 69.1% at
four years. After four years, 24%
showed steepening of the cornea
and 30.9% showed reduced visual
acuity, suggesting possible progression of the disease after four years.
Some note that these findings
are not statistically significant
in the current study, however.
“Confounding factors like thinner
corneal pachymetry expected after
CXL further make it challenging
to diagnose regression at its immediate resurgence,” says Clark
Chang, OD, director of the Contact
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
Lens division at the Center for
Keratoconus-Cornea and Laser Eye
Institute, Teaneck, NJ. “Therefore,
it is important to minimize or
eliminate extrinsic factors that
can exert mechanical strain on the
ocular surface, which presumably
can destabilize therapeutic effects
conferred by CXL.”
Clinicians must remain vigilant in
managing ocular comorbidities such
as dry eye and atopic or allergic
conditions, Dr. Chang says, as well
as educate patients about both the
risks of long-term regression and
the importance of compliance with
clinical monitoring to detect the
potential need for retreatment.
The study also found that 17.1%
of eyes in the study presented
topographic coupling effects—in
which flattening of one meridian is
accompanied by steepening of the
orthogonal meridian—suggesting
a compensatory biomechanical
response. “If we can control and
maximize such coupling effects,
then better visual outcome after
CXL may be achieved,” Dr. Chang
says. “Thus, it is essential for future
investigations to identify patient
variables associated with such
topographic coupling events, as well
as determine clinical characteristics
that may better predict the duration of CXL stabilization effects in
different patient subgroups.”
1. Padmanabhan P, Reddi SR, Rajagopal R, et al.
Corneal collagen cross-linking for keratoconus
in pediatric patients—long-term results. Cornea.
2017;36(2):138-143.
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My Perspective
By Joseph P. Shovlin, OD
Get to Know Your Genes
One day, genetic testing and gene therapy may help patients avoid corneal disease
altogether.
R
esearch suggests there
are nearly 500 different
eye-related diseases,
with more than 800
ocular and periocular
manifestations of systemic disease.
Hundreds of genes, if mutated, can
cause disease isolated to the eye.1
Fortunately, genetic testing can aid
health care providers in managing
inherited diseases. Specifically,
genetic testing is beneficial for (1) a
confirmational diagnosis, (2) newborn screening, (3) carrier screening and (4) forensic testing.1-3
Exciting new frontiers are
providing measures for pharmacogenomics, whole genome and
whole exome sequencing, and even
tumor analysis.2 The latter, for example, looks at genetic alterations
that drive tumor growth and the
genetics that help predict therapeutic response.
Identification of susceptibility
loci has helped researchers better
understand the complex pathophysiology of several ocular and
neurologic diseases.4
CLINICAL APPLICATIONS
Many recent findings in eye care
are a result of genetic testing, and
some are applicable to therapy
today:
• Though controversial, research
suggests there may be a different
response to the AREDS formula
based on specific genotypes, and
testing for the genotype for which
zinc supplementation may be
pro-inflammatory in patients with
macular degeneration could impact
therapy.
• For the cornea, genetic testing
6
is now available to identity Avellino’s corneal dystrophy.
• The Asper Biotech test screens
for 333 mutations in 13 genes for
corneal dystrophy.5
• Researchers have been investigating gene therapy to improve the
quality of donor tissue for corneal
grafts, which might decrease the
risk of graft failure and rejection.
THERAPY ADVANCES
The key is to target therapy with
testing prior to gene expression.
Gene augmentation—treatment
for deficient genes—is easier than
gene knock-out therapy (blocking a
gene causing a detrimental effect).4
For example, gene augmentation
therapy is now possible for Leber’s congenital amaurosis when a
RPE65 deficiency is found.
Using nanoparticles as vectors
for delivering DNA is an exciting
advancement.4,5 For example,
researchers recently used lentiviral-mediated genetic modification
of cultured endothelial cells to
deliver genes to the endothelium.5
Creating new viral vectors with
directed evolution is the key to
timely adoption. Researchers can
now create viruses in the lab to
maximize their diversity and can
promote the evolution of viruses,
through an artificial selection process, that have the traits researchers
need.3
KEEP PATIENTS INFORMED
As helpful as genetic testing can
be, it can raise both social and
ethical issues, and clinicians must
be careful to discuss the value and
limitations of genetic testing with
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
patients.6 When ordering tests, it
is the clinician’s duty to educate
patients on the likelihood that they
have a particular disease, the spectrum of disease possibilities (from
mild to severe), recurrence rates,
chance of passing the condition to
offspring, possible treatments and
reproductive alternatives.5,6
The ramifications of knowing
that you have the genes for a
particular disease without a current
treatment can be traumatic. Fortunately, patients are protected by
the Genetic Nondiscrimination Act,
which does not allow health care
insurers or employers to discriminate based on genetic predisposition or pre-existing conditions.5
T
he last two decades have seen
an explosion of research in
genomics, with rapidly expanding
genetic medicine. Gene therapy
specific to the cornea and anterior
segment is a particularly exciting
frontier, considering corneal disease
is responsible for a significant
amount of blindness worldwide.
Ocular gene testing and therapy
research is robust with a high priority in funding and should prove
fruitful in the very near future.
RCCL
1. Uthra S, Kumaramanickavel G. Gene therapy in ophthalmology. Oman Ophthalmol.
2009:2(3):108-10.
2. American Medical Association. Genetic Testing.
Available at www.ama-assn.org/content/genetic-testing. Accessed December 5, 2016.
3. Bethke W. The future of gene therapy. Rev
Ophthalmol. 2016:23(4):36-9.
4. Fritsche LG, Fariss RN, Stambolian D, et al. Age
related macular degeneration: genetics and biology coming together. Annu Rev Genomics Hum
Genet. 2014;15:151-71.
5. John T. Decoding the genetics of corneal
disease. Rev Cornea Contact Lenses. 2014
June:24-8.
6. Bateman B, Silva E. AAO Task Force on Genetic
Testing. Ophthalmol 2013;120(10):e72-3.
Guest Editorial
By Andrea P. Thau, OD, AOA President
Combating Online Contact Lens Sales
We must stand together to protect healthy vision and responsible enterprise.
O
ptometrists are fielding attacks from all
sides—not simply on
our profession, but
actions that could ultimately fracture the doctor-patient
relationship and potentially put
our patients’ health at risk. Online
contact lens retailers are primary
and long-time aggressors who use
deceptive practices, underhanded
loopholes and, sometimes, blatantly
illegal tactics to line their pockets
and build their bottom lines.
Like other physicians, eye doctors
take an oath and hold ourselves to
the highest standards to protect our
patients’ health. The oath guides
the way we practice and compels
us to advise patients of all their
options to restore, maintain or
enhance vision, as well as eye and
overall health. We do this within
a competitive marketplace bound
by laws and regulations, which
are constantly evolving as care
advances.
LEGISLATIVE LANDSCAPE
Unfortunately, the full picture of
the 2016 contact lens legislative and
regulatory landscape made it clear
online contact lens retailers are using misinformation and subterfuge
to divert attention away from their
unscrupulous business practices and
gain advantage in the marketplace.
The American Optometric
Association (AOA), doctors of
optometry and the patients we
serve are gaining ground in the fight
against these abusive and illegal
practices. We’ve exposed deceptive
tactics—such as 1-800-Contacts’
improper use of pre-checked order
forms to obtain copies of customer contact lens prescriptions.
This is further evidenced by the
Federal government’s suit against
1-800-Contacts for alleged activities
that “had the purpose, capacity,
tendency and likely effect of restraining competition unreasonably
and injuring consumers.”1
But along with wins, there are
sometimes setbacks, and the Federal
Trade Commission’s (FTC) recent
proposed rule is just that.
The AOA vigorously objects
to the FTC’s misguided proposal, which adds new prescription
requirements to the Contact Lens
Rule. The proposal makes clear that
the agency is hearing from those
who question whether doctors of
optometry are following the law
and does not take the illegal practices of some retailers into account.
With the active involvement of
our member doctors, state optometric associations, concerned physicians, as well as public health and
consumer protection organizations,
we are making the case for changes
and will not stop until our concerns
are clearly understood by agency
officials. This will not be a quick or
easy process, but one the AOA will
see through to the end.
A UNITED FRONT
We need the involvement and
activism of all of our colleagues to
get this proposal changed. The FTC
asked for public comments and is
now considering the issue further.
Moreover, we need to hold
internet sellers accountable, and the
AOA and state optometric associations are leading the effort by ag-
gressively building support for the
bipartisan Contact Lens Consumer
Health Protection Act. The bill
calls for bolstering patient safety
requirements, increasing accountability for internet contact lens sales
and reinforcing the distinction that
contact lenses are medical devices
and should be treated that way—all
of which the FTC should support.
The health and safety of the patients we serve is at the heart of this
matter, and the AOA, along with
member ODs, our paraoptometric
colleagues and optometric students,
will continue to fight for patient
safety. For every doctor of optometry in America, the surest way to
fight back against internet sellers
and the harm they cause patients is
to support the AOA and your state
optometric association.
O
ur past advocacy efforts show
that optometry is stronger
when we all work together, and we
ask every doctor to join in the fight
with the AOA to uphold patient
safety against online contact lens
retailers and their profit-driven
business practices.
1. Federal Trade Commission. Complaint In the Matter of 1-800 Contacts, Inc., a corporation. August 8,
2016. Available at www.ftc.gov/system/files/documents/cases/160808_1800contactspt3cmpt.pdf.
Accessed December 21, 2016.
ABOUT THE AUTHOR
Dr. Thau is president of the American
Optometric Association (AOA). She was
elected to the AOA Board of Trustees in
2007 and president in July 2016. Dr. Thau
also serves as chair of the AOA’s Executive
and Agenda Committees and is a member
of the Personnel Committee. She serves as
liaison trustee for the American Academy
of Optometry (AAO) and the College of
Optometrists in Vision Development (COVD).
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
7
Fitting Challenges
By Vivian P. Shibayama, OD
The Right Lens for a Corneal Scar
It’s not easy fitting a five-year-old with a specialty lens to correct irregular astigmatism.
C
hildren younger than
seven who need a
specialty contact lens
fitting can be some of
the most challenging
patients we encounter. Kids are vulnerable to amblyopia, which makes
the stakes even higher. The need for
specialty lenses at a young age can
occur for a variety of reasons, such
as aphakia, high refractive error,
anisometropia, iris defects, irregular
astigmatism from corneal scarring
or keratoconus. Let’s discuss a challenging case in which a child with
irregular astigmatism from a corneal
scar needed a specialty contact lens.
CASE REPORT
A five-year-old female presented for
a contact lens evaluation to correct
irregular astigmatism from a corneal
scar. Her pediatric ophthalmologist
referred her for a unilateral contact
lens fit over an eye that had a corneal dermoid removed at age three.
She was currently managed with
glasses and was patched two hours
per day with good compliance.
Medical history was positive for
Goldenhar syndrome and negative
for systemic medications. She exhibited no other ocular history and
neither did her family. Presenting
best-corrected visual acuity (VA)
was 20/20 OD, 20/50 OS. Her
current spectacle Rx was -0.50+0.50
x168 OS: +3.00+3.75x070.
Pupils were round and reactive to
light, with no relative afferent pupillary defect in either eye. Extraocular
movements were full OU. A slit
lamp exam demonstrated that the
lids were clear, the conjunctiva
white and quiet, the iris and lenses
clear, and the anterior chamber deep
8
and quiet OU. Exam of the corneal
surface revealed a clear right cornea
and an elevated 2.7mm horizontal
inferior temporal scar on her left
cornea—no staining or vessels OU.
Manifest refraction OD was plano
VA 20/20, OS was +4.25+5.50x075
VA 20/30-. Corneal topography revealed a flat cornea with steepening
at the corneal scar (Figure 1). Sim
K measured 46.17/40.62 OS and
5.62D of astigmatism.
DIAGNOSTIC FITTING
Although we started with a scleral
lens due to the irregularity of the
periphery, insertion was unsuccessful. The patient was very reactive
and could not fixate her eyes so that
the lens could be inserted without a
bubble inside the lens. After several
attempts, I decided to try a corneal
gas permeable (GP) lens instead. I
chose a large diameter intralimbal
GP design (GBL, Concise) as the diagnostic lens. This lens also features
a reverse geometry design in the mid
periphery, which would allow it to
clear the steep elevation in the mid
periphery without adding too much
clearance over the central cornea. I
first tried a 45.00D (7.50) lens based
off the average of the steeper curvature readings over the scar. The
lens was slightly flat over the cornea
scar with a somewhat tight edge
and pooling superior nasal. Overrefraction resulted in VA of 20/25.
I ordered the lens 0.75D steep to
take the lens pressure off the scar
with flatter peripheral curves than
standard to assist in distributing the
weight of the lens across the cornea.
First lens: Base curve 7.38, power:
+3.25, diameter:11.2, P1:0.4/9,
P2:0.4/10.5, P3:0.4/12.
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
DISPENSING
The patient presented with her
mother with no new complaints and
I inserted the lens (Figure 2). The
lens exhibited light one-third touch
inferotemporally with pooling over
the rest of the cornea. The peripheral edge was wide with good overall
centration of the lens and movement
with blink. VA measured 20/25 with
the GP in place OD. The patient’s
mother was instructed on care, insertion and removal, and advised to
build wearing time, starting at two
hours a day with the goal of eight to
10 hours a day.
FOLLOW-UP #1
One week later, the patient presented with complaints that the lens
hurt after a few hours of wear, and
she was unable to wear it more than
three hours per day. Some redness,
but no discharge, was observed.
Presenting VA was 20/25 OD with
the contact lens. No over-refraction
was measured. Fluorescein was
instilled, and I observed that the
lens had adhered to the cornea,
exhibiting little movement and was
decentered temporally over the scar.
With the lens removed to evaluate
the cornea, there was 1+ punctate
staining over the corneal scar.
Modifying the GP would unlikely
achieve better results, as opening the
periphery to increase movement and
increasing the vault over the scar
would likely still result in the lens
migrating towards the steep elevation of the scar. I decided to piggyback the GP with a soft lens.
I used a +3.00 Air Optix Night &
Day (Alcon) to create a buffer between GP and eye. I chose a higher
plus lens to aid in shifting the steep
Up to
10 CE
Credits*
14TH ANNUAL
EDUCATION
SYMPOSIUM
lubrication with
artificial tears. On
slit lamp exam
and instillation
of fluorescein,
the lens was
again decentering
temporally with
little movement.
Fig. 1. Topography of left eye. An overall flat cornea with When the lens
inferior temporal steepening at the corneal scar.
was removed, no
area centrally so the lens would
staining was observed. Other than
decenter less. On slit lamp exam, the the scar, the cornea was clear.
GP moved well over the soft lens.
Because any GP would most
VA was 20/30. Over-refraction of
likely shift towards the elevation, we
the combined system (-0.50) would
discussed using a scleral lens again
be added to the GP if the patient did and I performed an in-office evaluwell. I prescribed Polytrim (polyation, during which the patient was
very cooperative. I used a Europa
myxin B/trimethoprim, Allergan)
(Visionary Optics) fitting set and
for a few days to prevent infection
chose a 45.00D/16.0 diameter lens
and advised her to start lens wear
as the first diagnostic lens simply beafter finishing the antibiotic course.
Mom was again trained on insertion cause it was in the middle of the set.
Upon insertion, the child noted an
and removal and instructed to have
immediate improvement in comfort.
her daughter wear the lens no more
than four hours per day as long as
Slit lamp exam revealed excessive
the lens is comfortable.
clearance of about 450µm. When I
tried a 42D lens, it exhibited about
FOLLOW-UP #2
200µm of central clearance on
The patient presented the next
initial evaluation, which was ideal.
week. Though lens tolerance was
The lens landed outside the limbus
much improved, she didn’t think she and centered well. The periphery
could wear it more than four hours
appeared tight, exhibiting slight
per day, as she needed frequent
conjunctival vessel compression.
Given the child’s positive initial reaction, I ordered a 42.50/+6.25/16.0
diameter, 1 flat periphery lens to be
dispensed the next week. The base
curve was slightly steepened to compensate for the change in the sagittal
depth with a 1 flat periphery.
Optometric Cornea, Cataract
and Refractive Society
April 22-23, 2017
Marriott Del Mar
San Diego, CA
The meeting of the year for
ODs involved and interested
in advanced ocular disease
management, refractive
surgery, cataract surgery and
innovative technologies.
Interactive Workshops:**
• Therapeutics and
Post-Op Complications
• Pre-Operative Diagnostics
Up to 10* hours of COPE CE
will be provided to attendees.
See registration website for
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For more information contact:
Andrew Morgenstern, OD,
[email protected]
Clark Chang, OD
[email protected]
Visit www.occrs.org
Fig. 2. GBL lens on first dispense.
Note the light touch of the lens over
the area of the corneal scar.
SCLERAL LENS DISPENSE
At the second lens dispense a week
later, the patient hadn’t been wearing any lenses for the past week.
OPTOMETRIC CORNEA, CATARACT
AND REFRACTIVE SOCIETY
Administered by
Review of Optometry ®
*Approval pending
**Separate registration required. Agenda is subject to change.
Fitting Challenges
By Vivian P. Shibayama, OD
The scleral lens cleared the central cornea by about 200µm. The
fluorescein extended from limbus to
limbus and the lens landed on the
conjunctiva without impinging on
the sclera. VA was 20/25 OS. Mom
was trained on insertion, removal
and care. The patient was instructed
to return the following week.
FOLLOW-UP #3
One week later, the patient said she
was able to wear the lens for 10
hours a day without any complaint
(Figure 3). Uncorrected VA measured 20/20 OD and 20/25 OS. No
over-refraction was noted over the
left lens. The lens was finalized and
the patient was asked to return in
six months for a follow-up.
DISCUSSION
Several studies show that vision
rehabilitation of irregular astigmatism or high refractive error with
contacts lenses is more effective
than spectacles.1-4 GPs are able to
correct irregular astigmatism as well
as eliminate the aniseikonia from
unequal prescriptions when the
irregularity is unilateral.5,6 For children, the high oxygen material of
the lenses combined with involving
the parents in the care lowers the
risk for contact lens complications.7
Children younger than seven are
often too young to understand what
needs to be done, but old enough
to be traumatized by an aggressive
approach, which may give them a
negative association with the lens.
Using a soft approach is ideal,
and you should always tell the child
what you are doing and why. If you
can, show them that you and their
parents wear contact lenses. If a
child is particularly resistant to anything being inserted in the eye, send
preferable to a spectacle correction.
Additionally, the process of acclimating a child to lens wear can be
emotionally taxing on the parents,
and they need to be reassured they
are not hurting their child. Spending
time on this conversation is essential
to the child’s visual success.
Fig. 3. Scleral lens in place at first
follow-up. A white and quiet eye
after eight hours of successful wear.
them home with artificial tears or
even a soft contact lens to practice.
This will help acclimate the child to
the task, as with this patient.
The process of fitting a contact
lens can vary from child to child.
With younger or less cooperative
children, GP diagnostic lenses of
known base curves and their fluorescein patterns can help determine
corneal curvature.
To fit a corneal scar, the fluorescein pattern of an GP should exhibit
two-thirds pooling and one-third
light touch over the entire cornea.
The lens should center well and
move adequately to provide tear exchange for optimal corneal health.
In cases where GPs fail, sclerals can
be effective, as they are tolerated
well in the pediatric population.10,11
The lens can often compensate for
GP issues such as ocular surface disease, decentration or intolerance.12
EDUCATION IS ESSENTIAL
Despite vision improvement for
most children, studies indicate a
contact lens dropout rate as high as
36.8% in patients with unilateral irregular astigmatism.13 To help avoid
this, clinicians should ensure parent
buy-in and educate them on why
the contact lens is necessary. They
also need to understand the risk of
amblyopia and why a contact lens is
10 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
F
or children with irregular astigmatism or high refractive error,
vision rehabilitation should begin
right away to prevent amblyopia.
This case emphasizes the importance of using your full arsenal of
contact lens options to address the
different needs of each child.
RCCL
1. Luo W, Tong JP, Shen Y. Rigid gas permeable contact lens for visual rehabilitation in aphakic following
trauma. Clin Exp Optom. 2012;95:499-505.
2. Pieramici DJ, Sternberg P Jr, Aaberg TM Sr, et al. A
system for classifying mechanical injuries of the eye
(globe). The Ocular Trauma Classification Group.
Am J Opthalmol. 1997;123:820-31.
3. Netto AL, Fioravanti Lui AV, Fioravanti Lui GA.
Visual rehabilitation with contact lenses after ocular
trauma. Arq Bras Oftalmol. 2008;71:23-31.
4. Lin PW, Chang HW, Lai IC, Teng MC. Visual outcomes after spectacles treatment in children with
bilateral high refractive amblyopia. Clin Exp Optom.
2016;99:550-4.
5. Jupiter DG, Katz HR. Management of irregular
astigmatism with rigid gas permeable contact lenses. CLAO J. 2000;26:14-7.
6. Kanpolat A, Ciftci OU. The use of rigid gas
permeable contact lenses in scarred corneas. CLAO
J. 1995:2.
7. Shaughnessy MP, Ellis FJ, Jeffrey AR, Szcotka L.
Rigid gas permeable contact lenses are a safe and
effective means of treating refractive abnormalities
in the pediatric population. CLAO J. 2001-27:195-201.
8. Pradhan Z, Mittal R, Jacob P. Rigid gas-permeable
contact lenses for visual rehabilitation of traumatized eyes in children. Cornea. 2014;33:486-9.
9. Walters JL, Paules MG. Review of preclinical
studies on pediatric general anesthesia-induced
developmental neurotoxicity. Neurotoxicology and
Teratology. 2016 Nov 18. [Epub ahead of print].
10. Rathi V, Mandathara P, Vaddavalli P, et al. Fluid
filled scleral contact lens in pediatric patients: Challenges and outcome. Contact Lens and Anterior Eye.
2012;35(4):189-92.
11. Gungor I, Schor K, Rosenthal P, Jacobs DS. The
Boston scleral lens in the treatment of pediatric
patients. J AAPOS. 2008:12(3):263-7.
12. Pullum KW, Whiting MA, Buckley RJ. Scleral contact lenses: the expanding role. Cornea.
2005:24(3):269-7.
13. Ozkan B, Elibol O, Yuksei N, et al. Why do
patients with improved visual acuity drop out of
GP contact lens use? Ten year follow-up results in
patients with scarred corneas. Eur J Opthalmol.
2009:19:343-7.
Your job is about more than providing good patient care. To
succeed, you have to navigate changing healthcare policies, keep
up with the latest clinical advancements, manage your staff and
run a successful business. Zero in on the topics impacting every
aspect of your practice and career at SECO 2017, the largest
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Myopia MOVE
M
MOVE
OVE
on
the
Steady growth in the prevalence of this deceptively simple condition will expose half the world’s
population to visual impairment. Here’s what to expect and what we should do.
T
he general public has
traditionally considered
myopia a simple refractive condition correctable by spectacles and
contact lenses with limited impact
on permanent visual impairment.
This is not the case, however; myopia is increasingly associated with a
heightened risk of permanent vision
impairment, as evidenced by reports
of myopic macular degeneration as
a frequent cause of vision impairment and blindness in Asia and
Western nations.1-5
Myopia already affects a massive proportion of the population
in Asia.1 For example, Taiwan
has rates of myopia of up to 84%
in school children, and 97% of
19-year-old South Korean male
military conscripts are myopic.2,3
Myopia is also becoming a problem
beyond East Asia, with the United
States reporting increases in prevalence from 25% to 42% between
1972 and 2002, and high myopia,
in particular, increasing eightfold
from 0.2% to 1.6% in those older
than 30 over the same period.4 In
Australia, where myopia levels are
generally considered to be low, the
Sydney Adult Vascular and Eye
Study recently reported that almost
30% of 17-year-olds are myopic.5
Although individual studies
provide essential information on
the prevalence of myopia, they are
difficult to generalize, as they cover
specific ages, groups or places. For
effective planning, policymaking
and interventions regarding myopia,
we must organize and understand
the data to predict trends and estimate future prevalence.
THE GLOBAL PREVALENCE
A study by the Brien Holden Vision
Institute (BHVI), published in
Ophthalmology in 2016, reported a meta-analysis of the global
prevalence data on myopia and
high myopia since 1995.6 Using
the PubMed (National Library of
Medicine) database to review the
literature, this study highlights the
condition’s prevalence across the 21
regions of global burden of disease
(GBD), which are countries grouped
together based on their geographic
location and socioeconomic status
(http://ghdx.healthdata.org/countries). Evidence of varying prevalence over time enabled our research
team to create functions to predict
the future prevalence of myopia and
high myopia from 2000 through
2050 by decade. (see, “How
BHVI Estimated Prevalence Rates
Through 2050.”)
The model indicated the global prevalence of myopia affected
almost 23% of the population in
2000. More importantly, it predicted
that amount would grow to 50%
of the world’s population by 2050
(Figure 1). Nearly 1.5 billion people
were affected in 2000, and by 2050
this is expected to increase to almost
five billion.6
High myopia is also set to rise
from an initially low prevalence of
almost 3% in 2000 to close to 10%
in 2050. This equates to 163 million
people in 2000, and by 2050 almost
one billion people will be potentially
12 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
at risk of developing permanent
vision impairment and blindness
associated with high myopia.6
Approaching 2050, the difference in prevalence rates between
Asia and the rest of the world start
to decrease, with many regions
reaching a prevalence of more than
50%, presumably due to increasing
urbanization and socioeconomic
development. For example, in 2010,
the high-income Asia-Pacific nations
had a prevalence of 48.8%, while
Eastern Europe and North Africa
and the Middle East had prevalences of 25% and 14.2%, respectively.
ABOUT THE AUTHORS
Dr. Jong is senior research
fellow at the Brien Holden
Vision Institute (BHVI) in
Sydney, Australia, and a
visiting fellow at the University
of New South Wales (UNSW),
Australia.
Dr. Sankaridurg is program
leader for the Myopia Program
at BHVI and an associate
professor at UNSW.
Dr. Fricke is a consultant at
BHVI.
Dr. Naduvilath is head
biostatistician at BHVI.
Dr. Resnikoff is a consultant at
BHVI and a visiting professor
at UNSW.
Dr. Naidoo is CEO of BHVI, a
visiting fellow at UNSW and
founder of the African Vision
Research Institute, University
of Kwa Zulu Natal, South
Africa.
By Monica Jong, PhD, BOptom, Padmaja Sankaridurg, PhD, BOptom, Timothy R. Fricke, BOptom, MSc,
Thomas John Naduvilath, PhD, Serge Resnikoff, MD, PhD, and Kovin Naidoo, OD, PhD
annually, of which myopia was the
main cause.16 As a consequence of
rising myopia levels, the prevalence
of uncorrected refractive error and
the associated burden will increase.
High myopia also increases the risk
of potentially sight-threatening conditions such as glaucoma, myopic
macular degeneration, cataracts and
retinal detachment.17 One billion
people are predicted to be highly
myopic by 2050, and the number
of people with vision loss resulting
from high myopia is predicted to
increase sevenfold from 2000 to
2050.6 Based on these projections,
myopia is set to become a leading
cause of blindness worldwide.
IMPLICATIONS
As a consequence of the rising prevalence of myopia, there will be substantial demand for increased eye
care resources for refractive services,
such as spectacles and contact lenses, in correcting the refractive error
and treating myopia progression.
In addition, there will be a need for
managing and preventing high myopia–related ocular complications.
Uncorrected refractive error is already the primary cause of distance
vision impairment globally, affecting
108 million people.15 It is also the
second most common cause of global blindness.15 The economic burden
of uncorrected distance refractive error was estimated to be $202 billion
NEXT STEPS: MANAGEMENT
Many unanswered questions
remain. To intervene at the appropriate stage, we need to better
understand the risk factors associated with myopia onset and progression—such as ethnicity, lifestyle and
parental myopia. It is important to
regularly monitor population trends
and characteristics to identify risk
factors and adjust behaviors and
management accordingly to limit
Fig. 1. Estimated Global Prevalence of Myopia and High Myopia,
2000 to 2050
5,000
49.8%
Myopia
4,500
High Myopia
45.2%
4,000
3,500
39.9%
3,000
34.0%
2,500
2,000
28.3%
1,500
1,000
500
Source: Adapted from Holden BA, et al.6
WHY THE INCREASE?
The projected increases in myopia and high myopia are largely
considered to be driven by environmental factors and lifestyle changes,
such as reduced time outdoors and
increased near-based activities.1
Genetic predisposition is also a factor, but it cannot explain the rapid
changes in prevalence seen in such a
short timespan.7
Research suggests the high-pressure educational systems children
are subjected to at very young ages
in countries such as Singapore,
Korea, Taiwan and China may be a
major contributing lifestyle factor.1
Excessive use of electronic devices
could also play a role.1
Other factors thought to be involved in myopia development and
progression include light levels and
specific wavelengths, time outdoors,
vitamin D and peripheral defocus in
the corrected and uncorrected myopic eye, stimulating axial elongation.8 Different light levels, different
wavelengths and duration of light
have been shown to affect axial
elongation in animal studies, but are
yet to be tested in humans.8 Trials
conducted in Taiwan and China
indicate time outdoors reduces risk
of developing myopia, with less
myopia progression seen in summer
vs. winter months.9-11 The role of vitamin D in myopia is unclear; some
reports suggest it is linked with
myopia, while others have found
no association.12,13 Investigators
also found diet was not associated
with myopia in a group of healthy
children in Singapore.14
The BHVI study results show
that, in the year 2000, the majority
of myopia was occurring in those
younger than 40, reflecting the
major change in lifestyle in children
and young people over the last two
decades, especially in Asia.6 Due to
urbanization and development, similar lifestyle factors will likely spread
to other parts of the world that are
still developing.
Number of people (in millions)
But by 2050, the research suggests,
the gap will close, with Eastern
Europe reaching a prevalence rate
of 50.4%, North Africa and the
Middle East jumping to 52.2% and
high-income East Asia moving up
less significantly to 66.4% (Figure
2).6
9.8%
22.9%
6.1%
2.7%
4.0%
5.2%
2000
2010
2020
7.7%
0
2030
2040
2050
Year
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
13
MYOPIA ON THE MOVE
Fig. 2. Regional Prevalence of Myopia in 2000, 2030 and 2050
2000
2030
2050
15.2
Andean Latin America
36.2
50.7
46.1
Asia-Pacific, high income
58
66.4
19.7
Australasia
43.8
55.1
15.7
Caribbean
37.4
51.7
5.1
Central Africa
14.1
27.9
11.2
Central Asia
32.9
47.4
20.5
Central Europe
41.8
54.1
3.2
Central Latin America
12.3
22.7
38.8
East Africa
56.9
65.3
18
Eastern Europe
38.9
50.4
14.6
North Africa and Middle East
38.8
52.2
28.3
North America, high income
48.5
58.4
5
Oceania
12.5
23.8
14.4
South Asia
38
53
33.8
Southeast Asia
52.4
62
5.1
Southern Africa
17.5
30.2
15.6
40.7
53.4
14.5
Tropical Latin America
35.9
50.7
5.2
West Africa
13.6
36.8
21.9
Western Europe
44.5
56.2
0
20
40
Myopia Prevalence Per Region (%)
14 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
60
Source: Adapted from Holden BA, et al.6
Southern Latin America
the burden of rising myopia. For
example, myopia has traditionally
been treated with single vision spectacles and contact lenses, but now
we know there are other options.
Research has made considerable
headway in identifying optical
interventions that might aid in preventing the onset and progression
of myopia. Optical interventions
provide myopic defocus—bringing
the image in front of the retina to
slow axial elongation.18 The myopic
eye tends to have relative peripheral
hyperopia, and these interventions
address this key risk factor. These
strategies include bifocal spectacles,
multifocal soft contact lenses and
ortho-k—in combination with behavioral strategies such as reduced
near work and more time outdoors,
and pharmacological agents such as
low-dose atropine. All these methods can help reduce the number of
people with myopia progression.19
There is still much debate about
when to start myopia control,
what treatments should be used on
whom and at what age. Optical
treatments such as bifocal spectacles
and multifocal soft contact lenses
can be used full time as soon as
a child is becoming myopic, and
ortho-k is a good option if the child
is a suitable candidate in terms of
refractive error and their ability to
perform extended wear. Concerning
efficacy, the average slowing of
myopia achieved across the bifocal
spectacles, ortho-k and multifocal
soft contact lenses are comparable,
ranging from 35% to 50%.20-22
The choice often depends on the
patient’s lifestyle and the rate of
slowed progression achieved.
Low-dose atropine (0.01%) is
commonly prescribed for myopia
progression in places such as Hong
Kong, Taiwan and Singapore, and,
more recently, in some Western
nations, one drop daily before
sleep. Research shows the use of
pharmacologic treatments such as
low-dose atropine for myopia is
safe in those as young as six, with
the longest study being five years.23
The mechanism by which low-dose
atropine works to slow myopia
remains unclear, but it significantly
slows the change in the spherical
equivalent by 60% after two years,
although this is not seen in a change
in the axial length.23 Some caution
is still required, as the effects of
chronic treatment with low-dose
atropine are unknown, including
the overall level of myopia control
when combining behavioral, optical
and pharmacologic treatments.
Although consensus surrounding myopia management has not
yet been achieved, it is critical to
successfully address the issue of
myopia. The Brien Holden Vision
Institute hopes to further foster
the movement towards consenHow BHVI Estimated Myopia
Rates Through 2050
• Selected 145 relevant studies
from a pool of 4,288 PubMed
articles, representing 2.1 million
individuals with myopia.
• Combined myopia prevalence
data with world population
data and stratified data into age
cohorts in five-year increments.
• Defined myopia as spherical
equivalent ≤-0.50D and high
myopia as spherical equivalent
≤-5.00D.*
• Grouped countries by GBD
region for applicability to other
epidemiological studies. (Results
were extrapolated for GBD
regions lacking myopia data).
• Performed meta-analysis of
prevalence data, combined with
myopia change over time, to
project prevalence rates for each
decade from 2000 to 2050.
*Spherical equivalent ≤-0.50D, the most
commonly used myopia definition, is
beyond the refraction measurement error
and captures children at the start of their
progression. Spherical equivalent ≤-5.00D for
high myopia identifies people at higher risk of
pathologic myopia and, if uncorrected, causes
vision impairment equivalent to the World
Health Organization’s blindness definition.
sus through collaboration with
researchers, clinicians and health
bodies using our experience in advocacy in areas such as uncorrected
refractive error.
More research is required to
fully understand the mechanisms of
myopia development and progression and identify those at risk of
developing high myopia. Public
health advocates will also need to
develop wellness promotion strategies and provide resources such as
clinical guidelines to respond to this
significant public health challenge.
Industry can also take a leadership
role by working with researchers
and clinicians to develop FDAapproved myopia treatments that
will have a positive impact.
O
verall, the world is becoming
more myopic—a trend that
has significant financial and societal
implications. More importantly,
high levels of myopia pose a threat
to sight that reduces quality of life
and exposes those affected to greater health risks. Evidence suggests
myopia can be managed better by
reducing the risk of the eye becoming more myopic with a number of
lifestyle, optical and pharmaceutical
interventions. The BHVI will be
releasing the first online myopia
management education program for
optometrists in March 2017. Please
go to www.brienholdenvisioninstitute.org for details.
RCCL
1. Morgan IG, Ohno-Matsui K, Saw SM. Myopia.
Lancet. 2012;379:1739-48.
2. Lin LL, Shih YF, Hsiao CK, Chen CJ. Prevalence of
myopia in Taiwanese schoolchildren: 1983 to 2000.
Annals of the Academy of Medicine, Singapore.
2004;33:27-33.
3. Jung SK, Lee JH, Kakizaki H, Jee D. Prevalence of
myopia and its association with body stature and
educational level in 19-year-old male conscripts
in seoul, South Korea. Invest Ophthalmol Vis Sci.
2012;53:5579-83.
4. Vitale S, Sperduto RD, Ferris FL 3rd. Increased
prevalence of myopia in the United States between
1971-1972 and 1999-2004. Arch Ophthalmol.
2009;127:1632-9.
5. French AN, Morgan IG, Burlutsky G, et al. Prevalence and 5- to 6-year incidence and progression of
myopia and hyperopia in Australian schoolchildren.
Ophthalmology. 2013;120:1482-91.
Want to learn more?
Access the freely available study at:
www.sciencedirect.com/
science/article/pii/
S0161642016000257
6. Holden BA, Fricke TR, Wilson DA, et al. Global
prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmology. 2016 May;123(5):1036-42.
7. Lim LT, Gong Y, Ah-Kee EY, et al. Impact of parental history of myopia on the development of myopia
in mainland china school-aged children. Ophthalmology and Eye Diseases. 2014;6:31-5.
8. Smith EL 3rd, Hung LF, Arumugam B. Visual
regulation of refractive development: insights from
animal studies. Eye. 2014;28:180-8.
9. Wu PC, Tsai CL, Wu HL, et al. Outdoor activity
during class recess reduces myopia onset and
progression in school children. Ophthalmology.
2013;120:1080-5.
10. He M, Xiang F, Zeng Y, et al. Effect of time spent
outdoors at school on the development of myopia
among children in China: a randomized clinical trial.
JAMA. 2015;314:1142-8.
11. Donovan L, Sankaridurg P, Ho A, et al. Myopia
progression in Chinese children is slower in summer
than in winter. Optom Vis Sci. 2012;89:1196-202.
12. Williams KM, Bentham GC, Young IS, et al.
Association between myopia, ultraviolet B radiation
exposure, serum vitamin D concentrations, and
genetic polymorphisms in vitamin D metabolic
pathways in a multicountry European study. JAMA
Ophthalmol. 2017;135:47-53.
13. Tideman JW, Polling JR, Voortman T, et al. Low
serum vitamin D is associated with axial length and
risk of myopia in young children. European J Epidemiology. 2016;31:491-9.
14. Lim LS, Gazzard G, Low YL, et al. Dietary factors,
myopia, and axial dimensions in children. Ophthalmology. 2010;117:993-7e4.
15. Bourne RR, Stevens GA, White RA, et al. Causes
of vision loss worldwide, 1990-2010: a systematic
analysis. The Lancet Global Health. 2013;1:e339-49.
16. Fricke TR, Holden BA, Wilson DA, et al. Global
cost of correcting vision impairment from uncorrected refractive error. Bulletin of the World Health
Organization. 2012;90:728-38.
17. Flitcroft DI. The complex interactions of retinal,
optical and environmental factors in myopia
aetiology. Progress in Retinal and Eye Research.
2012;31:622-60.
18. Sankaridurg P, Holden B, Smith E 3rd, et al.
Decrease in rate of myopia progression with a
contact lens designed to reduce relative peripheral
hyperopia: one-year results. Invest Ophthalmol Vis
Sci. 2011;52:9362-7.
19. Sankaridurg PR, Holden BA. Practical applications to modify and control the development of
ametropia. Eye. 2014;28:134-41.
20. Cheng D, Woo GC, Drobe B, Schmid KL. Effect
of bifocal and prismatic bifocal spectacles on
myopia progression in children: three-year results
of a randomized clinical trial. JAMA Ophthalmol.
2014;132:258-64.
21. Si JK, Tang K, Bi HS, et al. Orthokeratology for
myopia control: a meta-analysis. Optom Vis Sci.
2015;92:252-7.
22. Li SM, Kang MT, Wu SS, et al. Studies using
concentric ring bifocal and peripheral add multifocal contact lenses to slow myopia progression in
school-aged children: a meta-analysis. Ophthalmic
& Physiological Optics. 2017;37:51-9.
23. Chia A, Lu QS, Tan D. Five-year clinical trial on
atropine for the treatment of myopia 2: myopia
control with atropine 0.01% eyedrops. Ophthalmology. 2016;123:391-9.
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
15
1 CE
Credit
(COPE APPROVED)
Fitting Multifocal Contact Lenses for
MYOPIA CONTROL
M
yopia affected
approximately one
and a half billion
people in 2010,
and that number
is expected to rise to nearly five
billion by 2050.1 It is the single
most significant cause of distance
vision impairment, and high
myopia (i.e., worse than -5.00D)
is associated with a number of
sight-threatening complications
such as myopic macular degeneration, retinal detachment,
cataract and glaucoma.2-4 This
significant burden highlights the
need for strategies and solutions
to reduce the risk of onset and
slow the progression in those
already affected by myopia.
STRATEGIES FOR CONTROL
Myopia is a complex trait influenced by a number of environmental and genetic factors, and
the mechanisms underlying onset
and progression are not fully
understood. Although there is
a great deal to learn about the
mechanisms of myopia and why
individuals respond differently to
different stimuli and treatments,
some behavioral, pharmaceutical
and optical strategies already
show promise in clinical trials
in combating myopia—many of
which can be incorporated into
current day practice.5-26
Prevention is obviously the
most effective strategy to reduce
the burden of myopia. Several
randomized clinical trials suggest
a lifestyle intervention with more
time spent outdoors reducing the
risk of onset.5,6 However, because
this involves education and behavioral modification in the years
prior to the onset of myopia,
comprehensive community-based
programs that involve parents,
caregivers, teachers, governmental and non-governmental organizations and eye care practitioners
(ECPs) must be implemented for
this approach to be effective.
Despite the crucial role ECPs play
in educating parents and communities, their role is limited by
the fact that first contact with a
practitioner usually comes after
the onset of symptoms and signs.
Once a patient is diagnosed
with myopia, the ECP becomes
the central care provider and is
integral to evaluating the risk of
further progression. ECPs now
have many options for correcting distance vision impairment
and slowing its progression.
These options include more time
spent outdoors, atropine therapy (including low-dose atropine
0.01%), spectacles (progressives,
peripheral defocus management
and executive bifocals), contact
lenses that impose myopic defocus across sections of the retina,
and orthokeratology.5-26
Of these various interventions,
contact lenses fare well in terms
16 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
of the risk-benefit ratio compared
with other interventions for myopia control. For example, atropine has greater efficacy rates but
an increased risk of side effects
compared with contact lenses; in
addition, myopia rebounds once
treatment is stopped.7,8 Clinical
trials and case studies show
specially designed contact lenses
slow myopia progression from
25% to 72% compared with
spectacles.9-21
Contact lenses used for myopia
control can be either bifocal or
multifocal soft contact lenses,
as well as the rigid contact lens
designs used in orthokeratology.
Investigators have proposed
ABOUT THE AUTHOR
Prof. Sankaridurg is the program
leader for the Myopia Program
at the Brien Holden Vision Institute. She was awarded her
BOpt degree from the Elite
School of Optometry, Chennai, India, in 1989, her PhD
in 1999 from the University of
New South Wales, Australia, and
her MIP in 2012 from University of Technology,
Australia. After working for a number of years
at the L.V. Prasad Eye Institute, India, as the
chief of Contact Lens Services, she took a
position at the Brien Holden Vision Institute
and the Vision Cooperative Research Centre.
She was appointed a conjoint professor at the
School of Optometry and Vision Science, University of New South Wales, Australia, in 2016.
She has been actively researching myopia for
approximately 13 years. She is also involved in
postgraduate supervision and manages the
institute’s Intellectual Property portfolio. She
has more than 50 articles in peer reviewed
journals, is a co-inventor on nine patents/
applications, has authored several book
chapters and has delivered many podium
presentations including keynote lectures.
These practice pearls aid in myopia management,
including avoiding onset and slowing progression in
patients of all ages. By Padmaja Sankaridurg, PhD, BOptom, MIP
WHERE TO BEGIN
All individuals presenting with
myopia should be assessed for
risk of progression based on
age, ethnicity, family history of
myopia and past history of progression. The ocular examination
should include a cycloplegic assessment of the refractive error. A
non-cycloplegic refraction often
results in a more myopic refraction, and the difference is greatest
in younger children and those
with low myopic, emmetropic
Photo: Brien Holden Vision Institute
several mechanisms to explain
their myopia control effect,
including: (1) contact lenses
correct or reduce accommodative
lag, which is considered a stimulus for eye elongation; (2) they
reduce the peripheral retinal defocus, which is considered to increase the risk of eye elongation
by shifting the image closer to the
retina; and (3) the lenses impose
myopic defocus across areas of
the retina, which is considered to
inhibit eye growth.16-21,25,26
These practice pearls can help
you better understand the use of
soft contact lenses for myopia
control and how to incorporate them into your practice.
Currently, no products are on
the market specifically for use in
myopia control; thus, this discussion is based on clinical trial data
on the use of multifocal contact
lenses for myopia control.
The Proclear
centerdistance
multifocal
using the Brien
Holden Vision
Institute’s
contact lens
optical quality
analyzer
demonstrates
two distinct
zones in the
optical zone of
the lens and a
flat peripheral
carrier.
and hyperopic refractive errors.27
Because of this, ECPs should note
that a patient without myopia
could be classified incorrectly
as having myopia; likewise, the
magnitude of myopia could be
found to be higher than it actually is in a patient with myopia.
ECPs can decide to fit contact
lenses based on an assessment of
the risk profile or at the request
of the patient or, in the case
of a child, the caregiver. When
fitting contact lenses for myopia
control, clinicians should take
into consideration the minimum
age at which contact lenses can
be fitted, contact lens design for
myopia control, tests to perform,
the wear and care schedule,
managing visual performance and
follow-up intervals.
Release Date: February 2017
Sankaridurg, PhD, BOptom, MIP
Expiration Date: February 1, 2020
Credit Statement: This course is COPE
approved for 1 hour of continuing education
credit. Course ID is 52285-CL. Check with
your state licensing board to see if this
counts toward your CE requirements for
relicensure.
Goal Statement: Myopia is the single
most significant cause of distance vision
impairment, and high myopia (worse
than -5.00D) is associated with a number
of sight-threatening complications—
highlighting the need for strategies and
solutions to reduce the risk of onset and
slow progression. This article discusses
the use of soft contact lenses for myopia
control and how to incorporate them into
your practice.
Faculty/Editorial Board: Padmaja
Joint-Sponsorship Statement: This
continuing education course is jointsponsored by the Pennsylvania College of
Optometry.
Disclosure Statement: The author’s
employer has a commercial interest in
myopia control.
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
17
FITTING MULTIFOCAL CONTACT LENSES FOR MYOPIA CONTROL
Let’s take a look at these considerations in more detail:
prescribing them.
In addition to correcting and
controlling progression of myopia, studies indicate children
and teenagers wearing contact
lenses had improved quality of
life with respect to appearance
and satisfaction with correction.29
However, not all children can
successfully wear contact lenses. Conditions such as allergic
conjunctivitis have an onset in
childhood and, in such instances,
contact lens wear may aggravate
or increase the risk of flare-up.
Clinicians should ask about any
previous history of allergic or
vernal conjunctivitis, and examinations should include an eversion of the tarsal conjunctiva.
Percent reduction in progression relative to control group (Spherical equivalent)
FITTING AGE
Studies show children as young
as eight can successfully manage lens insertion, removal and
care.17-21,25,28,29 Other clinical studies found children achieved the
required duration of lens wear
(including full-time lens wear),
and the reported duration of
lens wear was comparable with
that seen in adult contact lens
wearers.30 Evidence shows no
increased risk of complications
associated with lens wear in children compared with adults.30,31
While it is common practice to
teach both the child and the parent, the ECP should ensure the
child can independently manage
all aspects of lens wear before
HE ET AL. 2015
CONTACT LENS DESIGN
Bifocal or multifocal contact
lenses have proven effective for
myopia control.16-21,25,26
The lens design researchers found effective for myopia
control was a center-distance
multifocal that had two distinct
portions within the optical zone:
a central portion that corrected
for the distance refractive error and an outer zone that was
relatively positively powered
compared with the central portion.16-21 The relatively positive
power was intended to reduce
hyperopic defocus, induce myopic defocus or both across areas
of the retina. The tested lenses
were experimentally designed
with the exception of two trials
that used commercially available
multifocal soft contact lenses:
Acuvue bifocal (center distance,
alternating five ring bifocal,
11
Outdoors
34
WU ET AL. 2013
56
58
SHIH ET AL. 1999; 0.10%
SHIH ET AL. 1999; 0.25%
96
SHIH ET AL. 1999; 0.5%
77
CHUA ET AL. 2006; 1%
59
CHIA ET AL. 2012; 0.01%
Atropine
68
CHIA ET AL. 2012; 0.10%
75
CHIA ET AL. 2012; 0.5%
46
CHO ET AL. 2005 (LORIC)
56
WALLINE ET AL. 2009
36
KAKITA ET AL. 2011
Orthokeratology
43
CHO AND CHEUNG 2012 (ROMIO)
31
30
SANTODOMINGO ET AL. 2012
HIROAKA ET AL. 2012
79
ALLER ET AL. 2016
39
CHENG ET AL. 2015
50
ANSTICE AND PHILLIPS 2011
Soft contact lenses
32
33
LAM ET AL. 2014
SANKARIDURG ET AL. 2011
44
HOLDEN ET AL. 2012
29
WALLINE ET AL. 2013
20
HASEBE, 2014 PA PALS +1.5D
14
15
HASEBE, 2014 PA PALS +1.0D
SANKARIDURG ET AL. 2010
51
CHENG ET AL. 2014 +1.50, 3DBI
39
CHENG ET AL. 2014 +1.50
BERNTSEN ET AL. 2012
33
COMET 2
GWIAZDA ET AL. 2003
13
YANG ET AL. 2008
EDWARDS ET AL. 2002
Spectacles
24
17
11
LEUNG AND BROWN 1999
LEUNG AND BROWN 1999
46
38
Myopia control with various interventions. Note the efficacy of these interventions compared with standard, single
vision spectacles or contact lenses.
18 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
Vistakon) and Proclear multifocal
D (Coopervision).19,21
Depending on the lens design,
the central distance portion varies
in diameter, and the relative positive power is delivered as either
concentric rings or as a gradient
power rising from the center
to the periphery. The dioptric
magnitude of the relative positive
or plus power—which is fixed
for use across the population and
not individualized—commonly
ranging in power from +1.50D to
+2.50D. There is still a dearth of
information regarding whether
increasing the relative positive
power or providing individualized treatment is likely to deliver
improved myopia control.
ASSESSING FIT AND
PERFORMANCE
The initial lens selection should
be based on cycloplegic spherical equivalent refractive error
and appropriately adjusted for
vertex distance. The contact
lenses employed in clinical trials
were spherical lenses that masked
low amounts of astigmatism
(commonly <0.75D and based
on the spherical component of
the refractive error). Clinicians
should refer to the manufacturer’s guidelines for lens selection
wherever possible.
Patients generally find the first
few minutes of lens wear unsettling but tend to adapt quickly.
Clinicians should wait to evaluate
visual performance until 20 to
30 minutes after lens insertion.
To ensure a successful fit, ECPs
should examine and optimize the
lens centration and movement
before addressing visual performance. Issues with lens fit such
as decentration or excessive lens
movement on the eye may mimic
or increase the severity or frequency of symptoms associated
Practice Pearls on Myopia Control:
1. Your toolkit for myopia management should include
myopia control contact lenses.
2. Assess the risk of progression of myopia for a patient and
tailor the management based on the risk.
3. A cycloplegic assessment of the refractive error is
essential, particularly in children, as non-cycloplegic
refractive assessment often results in a more myopic
refractive error.
4. Children eight years and older can successfully be fit
with contact lenses and can independently manage
and care for their lenses. In children, clinicians should
examine the anterior segment before prescribing contact
lenses, including eversion and examination of the tarsal
conjunctiva.
5. Contact lens designs employed for myopia control are
multifocal or multifocal-like lenses with a portion of the
optical zone devoted to correcting the distance myopic
refractive error and the remainder being relatively positive
compared with the distance power by an average of
+1.50D to +2.50D.
6. Wait 20 to 30 minutes to allow lenses to settle prior to
examining lens fit and visual performance. Optimize lens
fit prior to measuring visual performance with the lenses.
7. A daily disposable option or a frequent replacement
schedule minimizes the risk of complications associated
with contact lens wear.
8. When fitting children with contact lenses, ensure the
children can independently manage lens insertion and
removal, as well as lens care procedures.
with multifocal lens wear such
as ghosting, poor contrast and
haloes.
Poor visual performance may
be related to a number of factors,
including: strength of the relative positive power in the optical
zone; power profile of the lens
(for example, concentric rings of
plus power vs. gradient increase
in plus power); pupil size; ambient illumination and contrast.
A thorough clinical evaluation
taking these factors into account
may determine if the patient
requires a change in lens fit, lens
design or simply reassurance that
the lens is properly fit. If clinicians perform over-refraction,
they should do so using a trial
frame rather than a phoropter to
minimize errors related to head
tilt and movement behind the
phoropter.
WEAR TIME AND
REPLACEMENT MODALITY
Patients should be advised to
wear myopia control contact
lenses for all waking hours, as
improved lens wear compliance
results in better outcomes.18 Also,
patients should have an up-todate spectacle prescription for
occasions when lens wear may
not be feasible.
Contact lens wear does not
appear to pose an increased risk of
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
19
FITTING MULTIFOCAL CONTACT LENSES FOR MYOPIA CONTROL
complications in children compared with adults.32,33 To reduce
the risk of complications associated with lens wear, whatever they
may be, ECPs should prescribe
a regimen that minimizes lens
handling and the consequent risk
of microbial contamination of the
lenses. Education is key, and ECPs
should emphasize the risks associated with overnight lens wear
such as increased risk of infection
and focus on properly training
patients in appropriate lens care
and handling techniques. A daily
wear, daily disposable or frequent
replacement schedule is often the
most successful approach.
Also, while it is common practice to teach both the child and
the parent, practitioners should
ensure the child is fully adept at
managing all aspects of lens wear
such as insertion and removal,
lens disinfection as well as taking
necessary steps to prevent adverse
events, such as avoiding lens wear
when unwell or avoiding use of
solutions other than those provided by the ECP.
For patients with myopia progression, a three- to six-month
follow-up schedule is ideal for
avoiding potential adverse effects
such as blurred vision. Any drop
in visual acuity of one line or
more or over-refraction of 0.25D
or more necessitates the need for
a refractive error assessment so
the lens power can be appropriately adjusted.
OUR RESPONSIBILITY
The rising prevalence of myopia
and its notably progressive nature
is an increasingly significant concern for ECPs and their patients.
While further research regarding
the underlying mechanisms of
myopia is needed, current data
points to contact lenses as a safe
and effective means of delivering
myopia control.9-21 Since progression of myopia is rapid in childhood, treatment strategies should
be directed mostly to children
and young adults, for whom
studies show contact lenses
provide a better risk-benefit than
other forms of myopia control.
Taking into consideration patient
expectations and their ability to
manage lens wear, ECPs should
opt for myopia control contact
lenses in treating individuals at
risk of onset and progression.
RCCL
1. Holden BA, Fricke TR, Wilson DA, et al. Global
prevalence of myopia and high myopia and
temporal trends from 2000 through 2050. Ophthalmology. 2016;123(5):1036-42.
2. Chen SJ, Cheng CY, Li AF, et al. Prevalence
and associated risk factors of myopic maculopathy in elderly Chinese: the Shihpai eye study.
Invest Ophthalmol Vis Sci. 2012;53(8):4868-73.
3. Sun J, Zhou J, Zhao P, et al. High prevalence
of myopia and high myopia in 5060 Chinese university students in Shanghai. Invest Ophthalmol
Vis Sci. 2012;53(12):7504-9.
4. Li T, Du L, Du L. Prevalence and Causes of
Visual Impairment and Blindness in Shanxi
Province, China. Ophthalmic Epidemiol.
2015;22(4):239-45.
5. Wu PC, Tsai CL, Wu HL, et al. Outdoor activity
during class recess reduces myopia onset and
progression in school children. Ophthalmology.
2013;120(5):1080-5.
6. He M, Huang W, Zheng Y, et al. Refractive
error and visual impairment in school children in rural southern China. Ophthalmology.
2007;114(2):374-82.
7. Chia A, Lu Q, Tan D. Atropine for the treatment of childhood myopia: safety and efficacy
of 0.5%, 0.1%, and 0.01% doses (Atropine for
the Treatment of Myopia 2). Ophthalmology.
2012;119(2):347-54.
8. Shih YF, Chin CH, Chou AC, et al. Effects
of different concentrations of atropine on
controlling myopia in myopic children. J Ocul
Pharmacol Ther. 1999;15(1):85-90.
9. Edwards MH, Li RW, Lam CS, et al. The Hong
Kong progressive lens myopia control study:
study design and main findings. Invest Ophthalmol Vis Sci. 2002;43(9):2852-8.
10. Gwiazda J, Hyman L, Hussein M, et al. A
randomized clinical trial of progressive addition
lenses versus single vision lenses on the progression of myopia in children. Invest Ophthalmol Vis
Sci. 2003;44(4):1492-500.
11. Sankaridurg P, Donovan L, Varnas, S, et al.
Spectacle lenses designed to reduce progression of myopia: 12-month results. Optom Vis Sci.
2010;87(9):631-41.
12. Leung, JT, Brown B. Progression of myopia
in Hong Kong Chinese schoolchildren is slowed
by wearing progressive lenses. Optom Vis Sci.
1999;76(6):346-54.
13. Yang Z, Lan W, Ge J, et al. The effectiveness
of progressive addition lenses on the progression of myopia in Chinese children. Ophthalmic
Physiol Opt. 2009;29(1):41-8.
14. Hasebe S, Jun J, Varnas SR. Myopia control
with positively aspherized progressive addition
lenses: a 2-year, multicenter, randomized,
controlled trial. Invest Ophthalmol Vis Sci.
2014;55(11):7177-88.
20 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
15. Berntsen DA, Sinnott LT, Mutti DO, Zadnik K.
A randomized trial using progressive addition
lenses to evaluate theories of myopia progression in children with a high lag of accommodation. Invest Ophthalmol Vis Sci. 2012;53(2):6409.
16. Anstice NS, Phillips JR. Effect of dual-focus
soft contact lens wear on axial myopia progression in children. Ophthalmology. 2011;118(6):115261.
17. Sankaridurg P, Holden B, Smith E 3rd, et al.
Decrease in rate of myopia progression with
a contact lens designed to reduce relative
peripheral hyperopia: one-year results. Invest
Ophthalmol Vis Sci. 2011;52(13):9362-7.
18. Lam, CS, Tang WC, Tse DY, et al. Defocus
Incorporated Soft Contact (DISC) lens slows
myopia progression in Hong Kong Chinese
schoolchildren: a 2-year randomised clinical trial.
Br J Ophthalmol. 2014;98(1):40-5.
19. Aller TA, Wildsoet C, Results of a one-year
prospective clinical trial (CONTROL) of the use
of bifocal soft contact lenses to control myopia
progression. Ophthalmic Physiol Opt. 2006;26
Suppl 1:1-67.
20. Holden BA, Sankaridurg P, Lazon de la Jara
P, et al. Decreasing peripheral hyperopia with
distance centre relatively plus powered periphery contact lenses reduced the rate of progress
of myopia : A 5 year Vision CRC study. ARVO E
abstract 6300. 2012.
21. Walline JJ, Greiner KL, McVey ME, Jones-Jordan LA. Multifocal contact lens myopia control.
Optom Vis Sci. 2013; 90(11):1207-14.
22. Hiraoka T, Kakita T, Okamoto F, et al. Longterm effect of overnight orthokeratology on
axial length elongation in childhood myopia: a
5-year follow-up study. Invest Ophthalmol Vis
Sci. 2012;53(7):3913-9.
23. Cho P, Cheung SW. Retardation of myopia
in prthokeratology (ROMIO) study: a 2-year
randomized clinical trial. Invest Ophthalmol Vis
Sci. 2012;53(11):7077-85.
24. Santodomingo-Rubido J, Villa-Collar C,
Gilmartin B, Gutiérrez-Ortega R. Myopia control
with orthokeratology contact lenses in Spain:
refractive and biometric changes. Invest Ophthalmol Vis Sci. 2012;53(8):5060-5.
25. Aller TA, Wildsoet C. Bifocal soft contact
lenses as a possible myopia control treatment:
a case report involving identical twins. Clin Exp
Optom. 2008;91(4):394-9.
26. Turnbull PR, Munro OJ, Phillips JR. Contact
lens methods for clinical myopia control. Optom
Vis Sci. 2016;93(9):1120-6.
27. Hu YY, Wu JF, Lu TL, et al. Effect of cycloplegia on the refractive status of children:
the Shandong children eye study. PLoS One.
2015;10(2):e0117482.
28. Walline JJ, Jones LA, Rah MJ, et al. Contact
lenses in pediatrics (CLIP) study: chair time and
ocular health. Optom Vis Sci. 2007;84(9):896902.
29. Cheng X, Xu J, Chehab K, et al. Soft contact
lenses with positive spherical aberration for myopia control. Optom Vis Sci. 2016;93(4):353-66.
30. Walline JJ, Guame A, Jones LA, et al. Benefits of contact lens wear for children and teens.
Eye Contact Lens. 2007;33(6.1):317-21.
31. Li L, Moody K, Tan DT, et al. Contact lenses in
pediatrics study in Singapore. Eye Contact Lens.
2009;35(4):188-95.
32. Sankaridurg P, Chen X, Naduvilath T, et al.
Adverse events during 2 years of daily wear of
silicone hydrogels in children. Optom Vis Sci.
2013;90(9):961-9.
33. Chalmers RL, Wagner H, Mitchell GL, et al.
Age and other risk factors for corneal infiltrative
and inflammatory events in young soft contact
lens wearers from the Contact Lens Assessment
in Youth (CLAY) study. Invest Ophthalmol Vis
Sci. 2011;52(9):6690-6.
CE TEST ~ FEBRUARY 2017
1.
2.
3.
4.
Which of these complications is associated with high myopia?
a. Retinal detachment.
b. Cataract.
c. Glaucoma.
d. All of the above.
What is the most effective strategy to reduce the burden of myopia?
a. Contact lenses.
b. Prevention.
c. Vision therapy.
d. Refractive surgery.
Studies show contact lenses can slow myopia progression by what percent?
a. 1% to 10%.
b. 10% to 20%.
c. 25% to 72%.
d. 60% to 70%.
Most clinical trials employ this type of contact lens design:
a. Center-distance multifocal.
b. Translating multifocal.
c. Hybrid multifocal
d. Concentric bifocal.
5.
At what age can clinicians consider prescribing myopia control contact
lenses to patients?
a. Six.
b. Eight.
c. Ten.
d. Twelve.
6.
Why should clinicians perform a cycloplegic refraction before prescribing
contact lenses for myopia control?
a. Avoid a more myopic refraction.
b. Check visual performance.
c. Examine the tarsal conjunctiva.
d. Adjust the lens power.
7.
Which of these complications can mimic or increase the severity or frequency of
symptoms associated with multifocal lens wear?
a. Part-time lens wear.
b. Vernal conjunctivitis.
c. Incorrect plus power.
d. Excessive lens movement.
EXAMINATION ANSWER SHEET
Fitting Multifocal Contact Lenses for Myopia Control
Valid for credit through February 1, 2020
Online: This exam can also be taken online at www.reviewofcontactlenses.com.
Upon passing the exam, you can view your results immediately. You can also view
your test history at any time from the website.
Directions: Select one answer for each question in the exam and completely darken the appropriate circle. A minimum score of 70% is required to earn credit.
Mail to: Jobson Medical Information, Dept.: Optometric CE, 440 9th Avenue, 14th
Floor, New York, NY 10001.
Payment: Remit $20 with this exam. Make check payable to Jobson Medical
Information LLC.
Credit: This lesson is approved for 1 hour of CE credit. Course ID is 52285-CL.
Sponsorship: Joint-sponsored by the Pennsylvania College of Optometry
Processing: There is an eight-to-10 week processing time for this exam.
Answers to CE exam:
A
B
C
1.
A
B
C
2.
A
B
C
3.
A
B
C
4.
A
B
C
5.
6.
7.
8.
9.
10.
D
D
D
D
D
A
B
C
D
A
B
C
D
A
B
C
D
A
B
C
D
A
B
C
D
Evaluation questions (1 = Excellent, 2 = Very Good, 3 = Good, 4 = Fair, 5 = Poor)
Rate the effectiveness of how well the activity:
1
2
3
4
5
11. Met the goal statement:
12. Related to your practice needs:
1
2
3
4
5
13. Will help improve patient care:
1
2
3
4
5
1
2
3
4
5
14. Avoided commercial bias/influence:
15. How do you rate the overall quality of the material? 1
2
3
4
5
16. Your knowledge of the subject increased: Greatly
Somewhat
Little
17. The difficulty of the course was:
Complex
Appropriate Basic
18. How long did it take to complete this course? _________________________
19. Comments on this course: _________________________________________
___________________________________________________________________
20. Suggested topics for future CE articles: ______________________________
___________________________________________________________________
Identifying information (please print clearly):
First Name
Last Name
Email
8.
9.
How long after lens placement should clinicians wait until evaluating visual
performance?
a. Visual performance can be evaluated immediately after lens placement.
b. Five to 10 minutes.
c. 20 to 30 minutes.
d. 30 to 45 minutes.
All of these can lead to poor visual performance, except:
a. Strength of the relative positive power in the optical zone.
b. Power profile of the lens.
c. Lens replacement modality.
d. Pupil size.
10. How long should patients be advised to wear contact lenses for myopia
control?
a. All waking hours.
b. Overnight.
c. Eight to 10 hours a day.
d. Six to eight hours a day.
The following is your:
Home Address
Business Address
Business Name
Address
City
State
ZIP
Telephone #
-
-
Fax #
-
-
By submitting this answer sheet, I certify that I have read the lesson in its entirety
and completed the self-assessment exam personally based on the material presented. I have not obtained the answers to this exam by fraudulent or improper means.
Signature: ________________________________________ Date: _____________
Please retain a copy for your records.
LESSON 113633, RO-RCCL-0217
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
21
10
TIPS
from an
Orthokeratology Expert
Don’t let misconceptions stop you from using this treatment
modality that can provide a huge benefit to patients with myopia.
By Cary M. Herzberg, OD
O
rthokeratology
(ortho-k) is one of
the more challenging
treatment modalities in an eye care
practitioner’s toolbox, especially
considering effective myopia control
treatment needs to begin by the
age of six or seven.1 As challenging
as these young patients may be,
treating them with corneal reshaping can be immensely rewarding.
Orthokeratology has grown dramatically internationally; in China,
for example, close to two million
ortho-k lenses have been fabricated.2
However, less than 300,000 lenses
have been dispensed in the United
States—less than 1% market share
of the entire contact lens industry.3
Additionally, the nature of our
practice environment for contemporary eye care practitioners (ECPs)—
which emphasizes low reimbursements and ever-increasing numbers
of patients—makes it difficult to
find the time to focus on corneal
reshaping. But with myopia on the
rise, it’s time we use all of our tools.
I feel ortho-k is the best possible
treatment for eligible patients; using
the human cornea in its new-engineered shape to limit the progression of myopia has proven hugely
successful in my practice. Here are
10 tips to help you successfully
integrate ortho-k into yours.
1
KNOW THE RISKS AND
BENEFITS
Over 80% of orthokeratology
fits on adolescents are for myopia
control.4 Yet, ECPs are still reluctant to embrace the procedure,
possibly because there are few
procedures with a higher perceived
risk than fitting adolescents with
ortho-k. Risk aversion may inform
some of this reticence, but a further
understanding of the benefits of the
procedure proves to overshadow
the potential risks such as microbial
keratitis, corneal abrasions, central
corneal staining, lens binding and
tear film instability. The FDA is
willing to consider even a 30%
reduction in myopia resulting from
use of a medical device as clinically
significant; orthokeratology—with
close to a 50% reduction—serves
as the gold standard.
Safety concerns tend to be based
more in perception than fact. There
are scores of studies showcasing
the safety of this procedure.5-8 Out
of the 5,000+ ortho-k lenses I’ve fit
in the last 25 years, I’ve only had
one incident of microbial keratitis.
Early diagnosis and treatment,
combined with effective antibiotic
therapy, kept this patient’s microbial keratitis episode from causing
vision loss. My longest wearing
ortho-k patient just passed year 25,
and his seven diopters of myopia
at age seven hasn’t changed. Many
of my patients are in year 15 to
20 and still wearing lenses safely.
While we have had our share of
corneal abrasions and superficial
punctate keratitis, these have been
easily remedied and haven’t negated
the many benefits ortho-k has provided to my patients.
22 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
Even spherical aberration, initially
thought to be a negative side effect
of ortho-k, actually offers many
positives when it comes to advanced
custom ortho-k lens design. For example, by manipulating the positive
asphericity in ortho-k designs, along
with reducing the size of the treatment zone, you increase the elevation of the reverse curve, resulting in
an increase in spherical aberration
with more effective myopia control.
Introducing a negative asphericity,
however, can help increase add
power while also manipulating
spherical aberration.
2
CONSULT AND EXAMINE
In my office, we ask that
patients attend a free consultation before making an appointment for an ortho-k evaluation. It is
crucial that parents accompany any
adolescent patients. Often, I find the
parents do little to explain ortho-k
to their children because they don’t
understand it themselves, and the
consultation ensures both the parent
and the patient are educated properly. During the consultation we
ABOUT THE AUTHOR
Dr. Herzberg has been
practicing in Aurora, Ill., for 40
years—25 of which he has
specialized in ortho-k. He is
co-founder and president of
the International Academy
of Orthokeratology and
Myopia Control (IAOMC) and
founder and co-president of
the American Academy of Orthokeratology
and myopia control (AAOMC). He serves
as a consultant to the contact lens industry
and lectures and writes on the topic of
orthokeratology and myopia control around
the world.
answer questions and provide literature on the procedure while also
gathering information about a patient’s eligibility. It’s also the perfect
time to evaluate first impressions of
the maturity level of an adolescent
patient. Finally, after reviewing the
risks and benefits, you should have
parents, and the child if he or she is
old enough, sign off on all the key
points of an informed consent.
During the initial examination to
determine suitability, clinicians must
thoroughly rule out all complicating
conditions. For example, the presence of any corneal pathology (such
as keratoconus) is a contraindication. Practice extra caution when
considering cases with irregular,
limbus-to-limbus or against-the-rule
astigmatism or decentered corneal
caps—particularly if you are new
to ortho-k. Factors such as dry eye
should always be dealt with prior to
fitting.
It is extremely important, especially when treating the pediatric
population, that your staff knows
how to gather this pertinent clinical
information so the appointment can
be flagged if they note complicating
factors.
3
EVALUATE AND ASSESS
Following the initial examination is the actual ortho-k
evaluation. This should begin with
topography, which is the standardof-care for ortho-k. The baseline
topography will remain the reference for a patient’s fitting throughout their lifetime of ortho-k use,
so it needs to be performed with
great precision, and it’s imperative
to take more than one topography
reading. It’s not uncommon to need
10 or more readings on a patient
per eye to arrive at an accurate
assessment of the cornea prior to
fitting, considering corneal topographers using a Placido disc are often
inaccurate and provide different
Topography needs to be near perfect
to ensure a proper fit.
The accumulation of ortho-k trial
sets over the last 20 years.
results each time a map is taken. It
can be challenging to know which
one of those 10 is the one to use as
the reference. In my practice, I take
an auto-k reading and match that to
the topographies I have taken until
I find the closest one to the topography reading. Avoid using topographies with missing data points or
irregularities caused by tear pooling
or lid infringement.
Topography provides valuable
information on the cornea itself,
including the much-needed eccentricity; however, be wary of a
topographer’s accuracy. Besides
pre-fit data, the evaluating treatment
progress is one of its greatest benefits. All of the necessary information
you need for evaluating the fit is
at your fingertips, including axial,
tangential, refractive, elevation
and difference maps. Axial maps
determine the radius of curvature
at each particular point, which is
helpful in determining the refractive
change. Axial maps are also good
for determining the type, shape and
position of any corneal astigmatism.
Tangential maps are best used for
lens positioning in ortho-k, while
refractive maps speak to the quality
of vision. Subtractive or difference
maps are ideal for showing the overnight change after ortho-k.
The ortho-k evaluation is also a
good time to discuss other considerations such as haloes and adaptation for moderate-to-high myopia.
Haloes in younger patients usually
aren’t an issue, particularly after explaining how they are integral to the
myopia control effect. The change
from the prolate to oblate surface
created after ortho-k causes haloes
as it defines a new myopic image
shell on the peripheral retina. Still,
it’s helpful to know how sensitive
patients are to slightly blurry visual
effects such as haloes at distance.
Education is a key to success, so
make sure parents and patients understand these myopia-controlling
devices are not intended to give the
ultimate in fine distance acuity but
rather are a method of reducing
myopia progression.
Prior to fitting any lenses, discuss
how the patient’s accommodative
system may need help with vision
training during treatment. This is
especially true with newer custom
designed lenses that address the lack
of peripheral defocus in patients
with low myopia by creating more
demand and a resulting moderately
high hyperopia after lens removal
during treatment (>1D).
4
SIGN A CONTRACT
If at this point all looks well
and all parties involved opt
for ortho-k, prepare a contract and
go through it with the patient and
parent before having them sign it.
The contract should address all
expectations and contingencies.
Possible side effects need to be
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
23
10 TIPS FROM AN ORTHOKERATOLOGY EXPERT
covered, and suitable alternatives
addressed. Lastly, payment expectations should also be included.
Always remember when structuring
your fees for this procedure to allow
an extra margin in your final fees
to account for additional lenses or
extra time needed to achieve the
necessary precision. This is especially important for myopia control,
where the initial lens selection may
fail to deliver a satisfactory result.
5
CHECK THE CORNEA
When performing ortho-k,
it’s imperative to consider
factors such corneal volume: the
more volume you have the easier it
is to move tissue, even with higher
myopia. Be wary of small, flat corneas due to low volume, as they can
test your fitting abilities, even in low
prescriptions. Extremely flat corneas
can also pose a challenge, especially
in higher prescriptions. For example, 34.00D is about as flat as you
can expect after ortho-k, so a 6D
myope with a flat K of 39.00D may
be out of reach. Remember, over
40 microns of elevation difference
between steep and flat meridians
usually means a toric alignment
zone with its increased complexity.
Eccentricity of the cornea is extremely important to know to help
you determine how much flattening
to expect on the cornea as you move
towards the periphery and whether a five curve or higher design
is warranted due to that change.
Familiarize yourself with your topographer’s intricacies and margins
of error, as most will either over
or understate the “e” value. When
possible, also evaluate the “e” value
with other methods such as a trial
lens fitting. This is done by determining the best fluorescein pattern
available underneath that trial lens.
Ortho-k designs are accurate to perhaps 5µm, and the human eye can
pick up a difference in patterns of
Clinicians should evaluate the
orthokeratology fit at the slit lamp
before dispensing.
roughly 10µm to 15µm, permitting
an accurate assessment of corneal
eccentricity and best-fit profile.
When taking topographies on
children, take note that they tend to
be more fearful and fidgety during
examinations. If you are unable to
acquire that “perfect” topography
reading, it may be best to send
the child home with eye drops to
practice keeping their eyes open and
inform the parents of the need for a
precise topography. Have the child
open their eyes wide as they instill
the drops. Often on return visits,
they are more relaxed, giving you
a better opportunity to document
their topography.
6
BE READY FOR
FITTINGS
The next step is fitting and
ordering the lenses. The most
popular methods for doing this are
empirically, through trial lens fitting
or custom design. Many ECPs forgo
trial lenses and order an empirical
or custom topographic design as
“trial” lenses. In 80% of cases, they
will work effectively and require
minimal, if any, changes.7 Even
though I have diagnostic data to
help fit a patient, I often feel a trial
fitting is much more accurate, as
24 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
it provides additional information
that helps me customize each fit. For
instance, I can evaluate possible lid
interactions such as overly tight lids.
When you are ready to trial fit,
be sure to have the necessary time
and space for ortho-k patients by
providing a reclining chair so they
can lay down with eyes closed for at
least 15 minutes. This is much more
valuable than open-eye assessment
for lens fit and treatment. A mere 20
minutes of wear will often correct
significant levels of myopia and
astigmatism.
Many practitioners instill a drop
of topical anesthetic before lens
insertion to aid a young patient’s
adaptation.
With many different trial set
diameters at my disposal, I can nail
covering 95% of corneal surface,
which is necessary for best results.9
7
DISPENSE AND FOLLOW
When the lenses have arrived
and passed inspection, bring
the patient into the office and insert
the lenses to make sure they fit well.
If the patient and parent are satisfied, educate them on safe insertion,
removal and care. If the patient is
under eight years of age, it’s likely
the parents will need to step in and
provide support here, which may
mean all of the insertion, removal
and care. Allow enough time in
your schedule for this process and,
again, make sure this time is reflected in your fee structure.
Once you have dispensed the
lenses, active follow up is necessary.
In my practice, we see the patient
the next day and then again in one
month. Further follow-up visits are
scheduled at three-month intervals.
If it’s a higher amount of myopia or
other factors such as high astigmatism are present, we ask patients
to come in for follow-up appointments at two weeks as well. We also
schedule the following year’s lens
replacements and evaluations during
the initial year.
I replace lenses for a child yearly
because I personally believe that
will provide the healthiest and safest
outcomes, given children cannot
legally take responsibility for their
decisions, particularly when it
comes to lens care.
8
ADJUST ACCORDINGLY
Effective myopia control
requires A-scans to determine axial length before and during
treatment. You should take a new
measurement every year. These
readings, along with any changes
in the over-refraction with ortho-k
lenses at six and 12 months after
initial fitting, will either confirm
successful myopia control or lead to
a new treatment strategy.
Modifications such as increasing
the Jessen factor, using newer designs relying on six or more curves
or using eccentricity in the base
curve can lead to a greater elevation of the reverse curve and better
myopic defocus in the periphery.
The Jessen factor is the amount of
lens flattening over and above the
patient’s current prescription needs,
which allows the eye to remain free
from myopia, even after all-day
wear. Research shows increasing
the Jessen factor and reducing the
treatment zone can create a better
myopic image shell in the peripheral
retina.10 Simply adding low-dose
atropine (0.01%) in addition to ortho-k also may lead to better control
without changing the lens.
Management decisions should
be based on any changes in the
axial length after the beginning of
treatment. Even high myopia is
within reach—although ortho-k
may only get you part of the way
there. Correcting at least 4D with
corneal reshaping and then the rest
with glasses can still reduce myopic
progression by at least 50%.11
9
DON’T STOP TOO SOON
A common mistake parents
make is assuming that, once
the riskiest years of myopic progression have passed, their child
should switch from ortho-k to daily
wear lenses or glasses. This is nearly
always the wrong route to take,
as many younger patients have no
desire to limit their much-improved
quality of life by making that
switch. Further, in my experience,
long-term wear of ortho-k lenses
shows no signs of increased risk. I
have many patients who have been
wearing their ortho-k lenses for
more than a decade with no signs of
any adverse corneal changes. In fact,
their corneas remain pristine even
after years of overnight wear.
I consult with my long-term
wearers at least once a year on their
success with the procedure. When
they are ready for LASIK or feel
wearing the lenses nightly is impacting their lifestyle, I wash them out
of their lenses. This process may
take up to six months to accomplish
in long-term wearers (>10 years).
10
WATCH YOUR
PATIENTS AND
PRACTICE GROW
Ortho-k can dominate a practice.
My specialty practice is now about
80% corneal reshaping, which has
translated into a healthy practice.
Once you decide to incorporate
ortho-k into your practice, be prepared for a younger patient base. At
the same time, my younger corneal
reshaping patients have proven
extremely loyal, and I have a special
opportunity to participate with parents in fostering their growth. While
kids may be resistant to parental
advice, they will often listen to an
authority figure such as their ECP.
Don’t waste that opportunity.
Taking a proactive role in the
myopia epidemic and incorporating
ortho-k into your practice can make
a positive difference in your young
patients’ lives. Controlling myopia
progression at age six or seven by
just 30% will eliminate 75% of all
of high myopia (>5D) cases and the
subsequent increased risk of ocular
pathology.12 Further, evidence shows
ortho-k is impactful on adolescents’
visual performance and binocular
function.1 The improvement in quality of life afforded by ortho-k lenses
is extremely rewarding to witness.
W
ith myopia rates increasing,
it’s time to fully consider all
the options at our disposal. As far
as I’m concerned, ortho-k is the
way of the future. Don’t waste the
opportunity to provide this amazing
specialty to your pediatric patients.
Taking the road less traveled can
indeed make all the difference.
RCCL
1. Eiden B. Lets not forget that most of us use two
eyes together; Binocular vision implications in
corneal reshaping treatment. CL Today Newsletter.
December 11, 2016. Available at www.clspectrum.
com/newsletters/contact-lenses-today/december-11,-2016. Accessed January 6, 2017.
2. Oh S. Statistical data in the field of orthokeratology and myopia control in the US and
the world. Korean Contact Lens Study Society.
Korean Ophthalmology Contact Lens Society. Nov
2016;9:79-85.
3. Nichols J. Contact lenses 2015. Contact Lens
Spectrum. January 1, 2016. Available at www.
clspectrum.com/issues/2016/january-2016/contact-lenses-2015. Accessed January 6, 2017.
4. Kojima R, Caroline P. IQ Scleral Lenses. Presented
at Vision By Design 2014., April 24-27; Chicago, Ill.
5. Walline JJ, Rah MJ, Jones LA. The children’s
overnight orthokeratology investigation (COOKI)
pilot study. Optom Vis Sci. 2004 Jun;81(6):407-13.
6. Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children
(LORIC) in Hong Kong: a pilot study on refractive
changes and myopic control. Curr Eye Res. 2005
Jan;30(1):71-80.
7. Davis RL, Eiden SB, Bennett ES, et al. Stabilizing
myopia by accelerated reshaping technique
(SMART)-study three year outcomes and overview. Adv Ophthalmol Vis Syst. 2015;2(3):00046.
8. Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol.
2009 Sep;93(9):1181-5.
9. Global OK-Vision. GOV General Fitting Guide.
Available at www.global-ok.com/html/GOVFittingGuide.html. Accessed January 12, 2017.
10. Chan B, Cho P, Mountford J. The validity of
the Jessen formula in overnight orthokeratology:
a retrospective study. Ophthalmic Physiol Opt.
2008;28(3):265-8.
11. Charm J, Cho P. High myopia–partial reduction
ortho-k: a 2-year randomized study. Optom Vis
Sci. 2013;90(6):530-9.
12. Holden BA, Fricke TR, Wilson DA, et al. Global
prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmology. 2016;123(5):1036-42.
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
25
RESHAPING
By Daddi Fadel, DOptom
W
ith myopia on
the rise, it’s
more important than
ever to treat
patients as early as possible.1-2
Luckily, eye care practitioners
have several treatment options
available, including corneal
reshaping with orthokeratology
(ortho-k). Several studies show the
effectiveness of ortho-k in slowing
myopia progression in children.3-8
Researchers found axial elongation
was 51% to 57.1% less compared
with a control group wearing spectacles or soft contact lenses.6,8
But many patients with myopia have astigmatism, which can
sometimes complicate ortho-k
therapy. Nearly one quarter of
patients wearing soft contact
lenses require astigmatism correction, and 32% of patients with
myopia present with astigmatism
of 0.75D or greater in both eyes.9
These statistics suggest the number
of patients with astigmatism is associated with the increasing of the
number of patients with myopia.
To effectively treat this patient
population, clinicians must find
creative alternatives to traditional
ortho-k therapy. This article takes
a closer look at the use of toric
ortho-k lenses for myopia control
in patients with astigmatism.
EFFICACY OF
TORIC ORTHO-K
Researchers have suggested toric
lenses can slow axial elongation in
Ortho-K
patients with myopia with astigmatism.10-11 A study investigating
the effectiveness of toric ortho-k
lenses for myopia control in children ages six to 12 with myopia
from 0.50D to 5.00D and withthe-rule astigmatism from -1.25D
to -3.50D found that, after one
year of therapy, the axial elongation in subjects wearing toric
ortho-k lenses increased by an average of 0.15mm.10 This was 58%
slower than the control group, all
of whom wore spectacles. After
two years of therapy, the axial
elongation in the toric ortho-k
group increased by 0.31mm, 52%
slower than the control group.10
In another study—comprised of
24 treated patients without a control group—researchers noted no
myopia progression and no alteration in the axial length in myopic
children ages nine to 16 after one
year of toric ortho-k lens wear.11
CLINICAL NEED
Ortho-k treatment with spherical
reverse geometry lenses presents
two significant problems for
patients with astigmatism, limiting
their use to with-the-rule astigmatism up to 1.50D and against-the
rule and oblique astigmatism up to
0.75D.12-15
First, a spherical accelerated
ortho-k lens on a toric cornea will
have poor centration because the
lens’s sagittal depth is equal in
each meridian and the cornea’s
sagittal depth is different in each
meridian. This leads to ‘smiley
26 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
face’ (high ride) or ‘frowny face’
(low ride) topography patterns, induced astigmatism, glare and poor
vision (Figures 1a and 1b).16-19 As
a result, symmetric reverse ortho-k
designs can only flatten the flattest
meridian, which may actually
cause the astigmatism to increase.16
A toric ortho-k design will extend
the bearing area of the lens circumferentially to improve both lens fit
and clinical outcome.
Second, spherical reverse
geometry lenses cannot achieve
the peripheral touch necessary to
ensure stabilization, centration
and properly modulated hydrodynamic forces. Ortho-k treatment is achieved by combining
two pressures: the positive push
force in the central cornea and the
negative pull force in the mid-peripheral cornea.20 The negative
fluid pressure necessitates a 360°
total touch in the landing zone to
prevent fluid outflow along the
steepest meridian (Figures 2a and
2b).21 Therefore, the total peripheral touch is important not only
ABOUT THE AUTHOR
Dr. Fadel is an optometrist
specializing in contact lenses
for irregular cornea, scleral
lenses and orthokeratology.
She has a contact lens
private practice in Italy,
where she designs special
customized contact lenses.
She lectures and publishes,
especially on contact lenses for the irregular
cornea, scleral lenses and ortho-k. She is the
founder and president of the Italian Academy
of Scleral Lenses (AILeS), a board member
of the Italian Academy of Contact Lenses
(AILAC) and a member of the Scleral Lens
Society (SLS). Email: [email protected].
Toric lenses can expand myopia management
to include patients with astigmatism.
for better lens stabilization and
centration, but also to modulate
the hydrodynamic forces that lead
to corneal flattening in each meridian.16 In case of limbus-to-limbus astigmatism, the semi-closed,
fluid-filled system in the reverse
zone is achieved only with a toric
ortho-k design.21
WHEN TO FIT
TORIC ORTHO-K
Corneal astigmatism can be classified as apical, limbus-to-limbus
or peripheral.22 In the apical form,
astigmatism is greater centrally
than peripherally. In limbus-to-limbus, central and peripheral astigmatisms are equal. Finally, in the
third category, astigmatism is
greater peripherally than centrally.
The evaluation between corneal
and refractive astigmatism can
either be equal or different.22
Research suggests toric ortho-k
lenses be used for apical astigmatism, measured with a corneal
topographer, higher than 1.75D,
limbus-to-limbus astigmatism
higher than 1.25D and peripheral
astigmatism higher than -1.00D. 22
Using the toric back optic zone is
recommended for corneal astigmatism that differs from refractive
astigmatism. If the axes of corneal
and refractive astigmatism do not
coincide, the optical and the alignment zones require different axes.22
A recent study suggests toric ortho-k use may be beneficial when
the sagittal height differential
between the two principal meridi-
ans is greater than 25µm, or 1.00D
of toricity.23 This might be better
managed with a toric ortho-k
design, especially for toric corneas. The majority of eyes looked
at in the study had a peripheral
astigmatism greater than central
astigmatism.
DIFFERENT DESIGNS
Since their first introduction at
the Global Orthokeratology
Symposium in 2005 for the correction of astigmatism, toric ortho-k
lens designs have varied across
studies and case reports.10,13,16,18,21,
24-28
CLINICAL STUDIES
A study involving patients with
astigmatism greater than 1.25D
at any principal corneal meridian orientation used a lens design
containing five toric zones, with
reverse curves in the second and
the fourth.21 This design is known
as the “full toric double reservoir.”
The researchers suggested that to
achieve an adequate effect with
a toric ortho-k lens, mechanical
and hydrodynamic forces must
occur differently in each corneal
meridian, with greater flattening
in the meridian where the myopia is greater. Results demonstrated an 85% change in initial
astigmatism.21
An additional study, with subjects age nine to 16, used a design
with reverse and alignment toric
zones, which are more appropriate for toric corneas because they
Figs. 1a and 1b. Above, superior
decentration of a spherical ortho-k
lens on a toric cornea with no
corneal touch in the steepest
meridians. Below, the topography
pattern of the same lens shows a
decentrated treatment zone forming
a ‘smiley face’ pattern.
allow for better centration.11 The
corneal astigmatism was gradually
decreased, resulting in a success
rate of 92.8%.11 This suggests that
toric ortho-k designs are able to
reduce moderate-to-high corneal
astigmatism.
CASE REPORTS
One case report used a toric alignment zone and spherical back optic
and reverse zone for a 13-year-old
patient with spectacle correction
of -4.25 -1.50x165° OD and -4.25
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
27
RESHAPING ORTHO-K
-2.50x180° OS.18 According to the
report’s authors, the advantage of
placing a spherical optic zone on a
toric cornea is that the flattest lens
meridian creates a normal ortho-k
effect while the steepest meridian results in a greater ortho-k
effect—leading to the correction
of the corneal astigmatism. Other
case reports used the same design,
as did the first studies on toric ortho-k lenses for astigmatism.10,13,26
These studies demonstrated a 95%
toric ortho-k first lens fit success
rate in correcting low-to-moderate
myopia in children with moderate-to-high astigmatism, which
was better than the trial lens rate
of 73.5%, as well as a reduction in
the axial elongation amount.10,13
In another case report, of a
22-year-old patient presenting with
-4.25 -3.75x8° OD and corneal astigmatism of -3.10x7°, the
authors fit a reverse ortho-k lens
with two toric zones: the reverse
and the landing.16 The correction
of high corneal astigmatism needs
a perfectly closed reverse zone in
each meridian to properly modulate the hydrodynamic forces,
allowing for separate corneal
flattening in each meridian. At
two months post-treatment, the
patient’s corneal astigmatism was
largely reduced, and the subjective
correction was cyl -0.50Dx8° with
uncorrected visual acuity (VA) of
20/20.16
One case report used a hexacurve (i.e., six back curves) design
with two back toric zones, as
well as optic and landing zones
for a 44-year-old patient with
mixed astigmatism in which the
cylindrical component was greater than the spherical, the patient
presented with + 1.00 -2.00x180°
OD and +1.25 -2.25x180° OS.27
The vertical meridian was steeper
than the horizontal meridian in
the midperipheral landing zone
Figs. 2a and 2b. At left, a toric ortho-k lens on a toric cornea showing 360°
total touch in the landing zone. At right, the topography pattern of the same
lens shows a centered flattening treatment zone.
and vice versa in the optical zone.
Three months after ortho-k fitting,
the subjective correction was
+0.50 -0.50x10° (uncorrected VA
of 20/16) OD and +0.25 -1.00x5°
(uncorrected VA 20/16) OS.
In a more recent case report, a
48-year-old female presented with
-0.75 -2.50x170° add 1.50D OD
and -1.50 -1.50x20° add 1.50D
OS.28 Her best-corrected VA was
20/16 in both eyes. The patient’s
cylindrical component was three
times larger than the spherical
component in the right eye, while
the two were equal in the left eye.
Also, she had refractive astigmatism higher than corneal astigmatism (i.e., -1.82D OD and -1.39D
OS) and low eccentricity. The
lens fit was a tetracurve toric with
optical, reverse and landing zones.
According to the author, having
the cylindrical component three
times higher or equal to the spherical component and the refractive
astigmatism greater than the
corneal astigmatism was necessary
for the toric optical zone. The toric
reverse and alignment zones promoted the negative and hydrodynamic forces needed for treatment,
better stability and centration of
the lens.
While these reports are not
conclusive, they do illustrate that
various designs have proven useful
for specific patients presenting
with-the-rule, against-the-rule or
28 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
oblique in any axis astigmatism
up to -4.00D. Additionally, they
show that possibilities exist for
correction of different corneal and
refractive toricity, as well as limbus-to-limbus astigmatism.
H
aving a wide range of toric
ortho-k lens designs available
expands the therapeutic options
for the vast majority of patients.
Practitioners can also design their
own lenses, whether through
contact lens fitting simulations in
free style upon the corneal map
with topography; empirical fitting
software using keratometry and
eccentricity through topography
and refraction data; or downloadable topography software.
Evidence suggests children and
adolescents with astigmatisms up
to 4.00D in all directions, even
limbus-to-limbus, can benefit from
ortho-k and myopia control, as
toric ortho-k lenses have proven
to be efficient in reducing moderate-to-high astigmatism and
slowing axial elongation.22
RCCL
1. Holden BA, Fricke TR, Wilson DA, et al. Global
prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmology. 2016;123(5):1036-42.
2. Holden BA, Jong M, Davis S, et al. Nearly 1 billion myopes at risk of myopia-related sight-threatening conditions by 2050 - time to act now. Clin
Exp Optom. 2015;98:491-3.
3. Walline JJ, Rah MJ, Jones LA. The children’s
overnight orthokeratology investigation (COOKI)
pilot study. Optom Vis Sci. 2004;81:407–13.
4. Cho P, Cheung SW, Edwards M. The longitudinal
orthokeratology research in children (LORIC) in
Hong Kong: a pilot study on refractive changes
NEW TECHNOLOGIES
Up to
& TREATMENTS IN
2017
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Eye Care
Credits*
REVIEW OF OPTOMETRY®
EDUCATIONAL MEETINGS OF CLINICAL EXCELLENCE
and myopic control. Curr Eye Res. 2005;30:71–80.
5. Kakita T, Hiraoka T, Oshika T. Influence of
overnight orthokeratology on axial elongation
in childhood myopia. Invest Ophthalmol Vis Sci.
2011;52:2170–4.
6. Zhu MJ, Feng HY, He XG, et al. The control effect of orthokeratology on axial length elongation
in Chinese children with myopia. BMC Ophthalmol.
2014;14:141.
7. Li SM, Kang MT, Wu SS, et al. Efficacy, safety
and acceptability of orthokeratology on slowing
axial elongation in myopic children by meta-analysis. Curr Eye Res. 2016;14:600-8.
8. He, M, Du, Y, Liu, Q, et al. Effects of orthokeratology on the progression of low to moderate
myopia in Chinese children. BMC Ophthalmology.
2016;16:126.
9. Young G, Sulley A, Hunt C. Prevalence of astigmatism in relation to soft contact lens fitting. Eye
Contact Lens. 2011 Jan;37(1):20–5.
10. Chen C, Cheung SW, Cho P. Myopic control
using toric orthokeratology (TO-SEE study). Invest
Opthalmol Vis Sci. 2013;54:6510–7.
11. Luo M, Ma S, Liang N. Clinical efficacy of toric
orthokeratology in myopic adolescent with
moderate to high astigmatism. Eye Sci. 2014
Dec;29(4):209-18.
12. Ruston D, Van Der Worp E. Is ortho-k ok?
Optometry Today. 2004 Dec;17:25-32.
13. Chen CC, Cheung SW, Cho P. Toric orthokeratology for highly astigmatic children. Optom Vis
Sci. 2012;89:849-55.
14. Mountford J, Pesudovs K. An analysis of the
astigmatic changes induced by accelerated orthokeratology. Clin Exp Optom. 2002;85:284–93.
15. Cheung SW, Cho P, Chan B. Astigmatic
changes in orthokeratology. Optom Vis Sci.
2009;86:1352–8.
16. Baertschi M, Wyss M. Correction of high
amounts of astigmatism through orthokeratology.
A case report. J Optom. 2010;3:182-4.
17. Chan B, Cho P, Cheung SW. Orthokeratology
practice in children in a university clinic in Hong
Kong. Clin Exp Optom. 2008;91:453–60.
18. Chan B, Cho P, De Vecht A. Toric orthokeratology: a case report. Clin Exp Optom. 2009;92:38791.
19. Mountford J, Pesudovs K. An analysis of the
astigmatic changes induced by accelerated orthokeratology. Clin Exp Optom. 2002;85:284–93.
20. Mountford J, ed. Orthokeratology: Principles
and Practice. Oxford: Butterworth Heinemann;
2004;69–107.
21. Pauné J, Gardona G, Quevedo L. Toric double
reservoir contact lens in orthokeratology for astigmatism. Eye Contact Lens. 2012;38:245-51.
22. Pauné J. From bowtie to casual: dealing with
toric corneas in ortho-k. Lecture at GSLS, January
21-24, 2016; Las Vegas, NV.
23. Kojima R, Caroline P, Morrison S, et al. Should
all orthokeratology lenses be toric? Poster presented at GSLS, January 21-24, 2016; Las Vegas,
NV.
24. Baertschi M. Short and long term success with
correction of high astigmatism in OK. Lecture at
the Global Orthokeratology Symposium, July 2831, 2005; Chicago, IL.
25. Beerten R, Christie C, Sprater N, Ludwig F.
Improving orthokeratology results in astigmatism.
Poster presented at the Global Orthokeratology
Symposium, July 28–31, 2005, Chicago, IL.
26. Chen C, Cho P. Toric orthokeratology for high
myopic and astigmatic subjects for myopic control. Clin Exp Optom. 2012;95:103–8.
27. Calossi A. Mixed astigmatism treated with a
dual-toric ortho-k design. Contact Lens Spectrum.
2013 Feb;28:49.
28. Fadel D. Unusual clinical cases in orthokeratology. Review of Cornea & Contact Lenses. Jun,
2016:22-27.
CHARLESTON
MARCH 24-26, 2017
Join Review of Optometry’s New Technologies & Treatments
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CONTACT
LENSES
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Rooms limited. **Separate REVIEW
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29
Photos ©istock.com/JobsonHealthcare
Keys to a
r
t
i
c
a
i
d
Pe Soft Lens Fitting
A
s eye care practitioners (ECPs), we are
often faced with the
question, “How old
does my child need
to be before he can wear contact
lenses?” Although answers to this
question will vary, most doctors feel
confident in fitting children older
than 10 in contact lenses. Younger
children such as toddlers (from one
to three years of age) can also be
safely and successfully fit in contact
lenses when they are necessary to
enhance visual function or provide
therapeutic benefits. Important
considerations when fitting children
in contact lenses include: the benefits of lenses for the child, the risks
associated with fitting the child in
contact lenses and whether the child
and parents are ready for contact
lens wear. Although fitting pediatric
and adolescent patients in contact
lenses seems intimidating, these
patients are often less complex and
more compliant than adult patients.
Unpacking these considerations can
boost your clinical knowledge and
give you the confidence to care for
this patient population.
BENEFITS TO FITTING
PEDIATRIC PATIENTS
For the adult population, improved
cosmesis is one of the most common
reasons patients choose contact
lenses over spectacles—and the
same could be said about pediatric patients. The ACHIEVE study
found children wearing contact
lenses felt significantly better about
themselves in the areas of athletic
competence, social acceptance and
physical appearance compared
with study participants wearing
spectacles.1 In children who are
not compliant with spectacle wear
because of cosmetic concerns,
contact lenses can lead to an
overall improvement in compliance
with refractive correction. This is
particularly important for children
with significant refractive errors, as
contact lenses will increase the field
of view particularly well in patients
with a high refractive error. Patients
with corneal irregularities or high
refractive errors may experience
improved visual acuity and comfort
with contact lenses. Children with
significant anisometropia benefit
from the decrease in aniseikonia
with contact lens wear compared
with spectacle wear, which not only
decreases asthenopia, but also can
improve binocularity.2
CONCERNS FOR CLINICIANS
One of the first concerns that many
practitioners have when fitting
children in contact lenses is the
potential increase in chair time.
Contrary to popular belief, fitting
a young child does not necessarily
take more time than fitting an older
child or an adult. The Contact Lens
In Pediatrics study found that it
takes, on average, only 15 more
minutes to fit children age eight to
12 compared with children older
than 12.3 Most of this extra time
was spent on insertion and removal
training, a task that can generally
30 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
be delegated to staff members.
Another notable concern clinicians
have in fitting children—particularly younger ones—in contact lenses
is the risk of an adverse event.
However, younger children are actually less likely to have an adverse
event during contact lens wear than
teenagers and young adults, and
microbial keratitis is uncommon in
this population.4
READY OR NOT
(TO WEAR CONTACTS)
Determining if a child is ready
for contact lens wear is one of the
most challenging parts of the fitting
process. Although most parents ask
at what age we begin fitting contact
lenses, the patient’s age is generally
not the limiting factor. The pediatric
population is not homogeneous,
and each patient must be treated
individually. While some children as
young as seven may prove ready for
contact lens wear, some adolescents
are not good candidates.
Often to the caregiver’s surprise,
ABOUT THE AUTHORS
Dr. Jenewein completed a
residency in pediatrics and
binocular vision at Nova
Southeastern University.
She is an assistant
professor at Salus University
Pennsylvania College of
Optometry.
Dr. Bhagat is a faculty member
at the Pennsylvania College
of Optometry at Salus
University. She specializes
in managing ocular surface
disease and fitting specialty
contact lenses.
From infancy to adolescence, contact lenses prove a viable
and beneficial treatment option for a range of conditions.
By Erin C. Jenewein, OD, MS, and Kriti Bhagat, OD
the best resource for
pia, either by overplussing
answering the question
the non-amblyopic eye
of a child’s readiness is
to cause blur significant
the parents or guardians
enough to switch fixathemselves. Questioning
tion to the amblyopic eye
parents about the overall
or using a lens with an
responsibility level of the
opaque pupil to occlude
child will help to deterthe non-amblyopic eye.
mine if the child is ready
When using the plus
At left, a custom prosthetic lens decreases the amount
for the responsibility of
therapy, the lens-induced
of light entering the pupil and the cosmetic appearance
contact lens wear. Are
blur must be greater than
of the iris irregularity. At right, an inferior iris coloboma
causes increased light sensitivity and haloes around
they able to take responthe blur experienced by the
objects.
sibility for homework
amblyopic eye.6
or chores at home? Does the child
Additionally, tinted lenses can
the best option for the pediatric pamake their bed every morning and
be fit for patients with achromatient, regardless of the patient’s age.
keep a clean room? Will they retopsia or other cone dystrophies to
In these cases, parental motivation
member to remove the lenses before and support is the key to successful
decrease photophobia and enhance
bed every night and clean them
contact lens wear. Children who are color perception. Patients with
properly? The parent can also give
achromatopsia often prefer red,
aphakic—either from congenital
insight into the child’s personal hyaphakia or from cataract removal at magenta or brown lenses in lieu of
giene, which can impact their ability an early age—are often fit in contact wearing tinted spectacles. Although
to properly care for contact lenses.
the contact lens tint can be seen
lenses as infants or toddlers. Infants
Both patient and parent motivaunder the slit lamp, it is not detectand toddlers with extremely high
tion is essential to successful lens
able under normal viewing condirefractive error or high amounts of
wear in pediatric patients. If a child
tions, providing a more cosmetically
anisometropia may benefit from
is reluctant to wear lenses, it can be
appealing option. Colored lenses
contact lens wear to improve acuity
challenging to successfully fit them
can decrease photophobia, improve
and binocularity.
in contact lenses. Similarly, if a parvision and provide better cosmesis
Contact lenses can also be used
ent is reluctant to allow a child to
for patients with iris abnormalities
for penalization therapy in amblyowear lenses, it may be an indication
such as iris coloboma and aniridia.
the parent realizes the child is not
Pediatric patients with corneal
ready for contact lens wear.
irregularities may experience better
vision as well as increased comfort
SPECIAL INDICATIONS
with contact lenses.
Some pediatric patients who may
CHOOSING THE RIGHT LENS
not be ideal candidates for contact
Options for fitting children in conlens wear may, nevertheless, need to
tact lenses are similar to those with
be fit in contact lenses to improve
During a prostehtic lens fitting,
contact lenses can be layered to
any other age group. Soft lenses are
vision, comfort or binocularity. The
show the patient how the final
the most commonly used modality
overwhelming benefits of contact
product may look. Here is an
for general refractive cases such
lenses over spectacles in these paoccluded pupil contact lens with a
as myopia, hyperopia and regular
tients may make contact lens wear
brown underprint layered on top.
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
31
astigmatism. Many manufacturers
offer extended range parameters
for patients with high amounts of
myopia and hyperopia, keeping the
overall cost to a minimum for the
patient and avoiding the need to
switch to custom soft lenses.
Daily lenses decrease the likelihood of contact lens-related adverse
events. Daily disposables can also
be easier for children to handle,
eliminating the need for cases and
solution bottles.5
Children with aphakia, significant
corneal cylinder, irregular corneas
or ocular surface disease can be fit
with rigid gas permeable lenses,
including scleral lenses. When fitting
rigid lenses in children, it may be
beneficial to use a Burton lamp or a
Bluminator for lens evaluation outside of the slit lamp. This allows the
child to sit comfortably in a stroller
or parent’s lap during the lens evaluation. Prosthetic contact lenses are
an option for children with iris or
corneal irregularities. These lenses
can help decrease photophobia,
diplopia or improve cosmesis.
INSERTION AND REMOVAL
Training in the pediatric population
can be slightly more challenging
than in adult patients. Parents or
Even with a lighter iris, it’s hard to
tell a patient is wearing a tinted
contact lens, which help avoid the
use of red glasses.
guardians should be present to
listen to the instructions given to the
pediatric patient so the parent also
learns about proper contact lens
care in case they need to assist the
child. This is crucial for children too
young to insert and remove the lenses themselves, as the parent will be
handling this process for the child.
With every new pediatric patient,
there is always an insertion and removal training in-office. For parents
of infants and toddlers, clinicians
should stress the importance of having a secure hold of the infant’s head
and body. Many times, this becomes
a two-person effort, as one person
holds the infant while the other
inserts or removes the contact lens.
For children able to insert and remove lenses on their own, clinicians
should begin by emphasizing the
need to wash your hands before insertion and removal. Generally, the
practitioner places the lenses first,
so the child will have the lenses in
during the fitting process. Therefore,
training will entail teaching removal
skills first, followed by lens storage
and ending with insertion techniques. It is important to guide the
child the first time to help increase
confidence and then let them do it
on their own. This will show them
they can do it and indicate they may
be ready to take the lens home.
Clinicians should watch the child
insert and remove the lenses at
least twice before dispensing. This
ensures patient and parent have the
proper technique and are comfortable with the lenses. If the first training is unsuccessful, stop before the
patient and parent become frustrated and have them return to attempt
training on a different day.
Laying a towel over the sink drain
can help young patients avoid losing
lenses, and labeling solution bottles
and contact lens boxes and cases
carefully can avoid misusing the
solution or wearing incorrect lenses.
32 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
COMPLIANCE
Children are more likely to share
their lenses with friends, so it is
important to educate them that they
cannot do so with anyone else or
allow anyone try their lenses on. As
with any medical device, compliance
is always an issue. A handout that
details how lenses are to be worn
and the proper care method can
help with this. Written instructions
that includes the solution names,
replacement schedules, wearing time
and signs and symptoms of common complications can be extremely
helpful. Regardless of age, clinicians
should also warn against swimming
in lenses, and stress the need to
always rub the lenses with solutions,
store them with new solution each
night and replace the case every
three months.
M
any pediatric patients can
easily and safely use contact
lenses, even young children, with
proper oversight. Contact lenses
can provide improved confidence,
better visual acuity, higher levels of
comfort and better potential for binocular vision in pediatric patients.
Although fitting young children
can be intimidating at first, it can
be equally rewarding for both the
patient and practitioner.
RCCL
1. Walline J, Jones L, Sinnott L, et al. Randomized
trial of the effect of contact lens wear on self-perception in children. Optometry and Vision Science.
2009;86(3):222-32.
2. Winn B, Acherley RG, Brown CA, et al. Reduced
aniseikonia in axial anisometropia with contact
lens correction. Ophthalmic Physiological Optics.
1988;8(3): 341-4.
3. Walline, J, Jones L, Rah M, et al. Contact
lenses in pediatrics (CLIP) Study: chair time and
ocular health. Optometry and Vision Science.
2007;84(9):896-902.
4. Wagner H, Richdale K, Mitchell G, et al. Age,
behavior, environment, and health factors in the
soft contact lens risk survey. Optometry and Vision
Science. 2014;91(3):252-61.
5. Chalmers RL, Hickson-Curren SB, Keay L, et al.
Rates of adverse events with hydrogel and silicone
hydrogel daily disposable lenses in a large postmarket surveillance registry: the TEMPO Registry. Invest
Ophthalmol Vis Sci. 2015;56(1):654-63.
6. Walline J, Rah M. Contact lenses for amblyopia
Treatment. Contact Lens Spectrum. 2008. Available
at www.clspectrum.com/issues/2008/november-2008/treatment-plan. Accessed January 17,
2017.
IT’S TIME
TO SEE A
SPECIALIST.
(For your practice, that is.)
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patient care—but when it comes to running your private practice,
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MARCH 1, 2017
Georgia World Congress Center | Atlanta, GA
Medical professionals in all fields will
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REGISTER TODAY at www.seco2017.com/medpro360
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BONUS! Program registration includes a FREE one-year subscription for
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RO0217_House Seco Med.indd 1
1/17/17 3:54 PM
The GP Experts
By Robert Ensley, OD, and Heidi Miller, OD
Treating Infantile Aphakia: Think GPs
This lens modality is a great alternative to soft contact lens correction.
Photo: Viola Kanevsky, OD
Too steep a fit results in inferior
decentration and accummulation of
bubbles underneath the lens.
age.4 However, contact lenses can
be fit on infants and may even be
a preferable long-term option. The
Infant Aphakia Treatment Study
Contact Lens Experience, which
compared contact lens correction
for unilateral aphakia with IOL
implantation for children between
one and six months of age, showed
visual acuity outcomes were similar
at age one and four and a half.4 The
rate of adverse events was lower in
the study’s contact lens wearers, and
few patients in that group required
additional intraocular procedures.4
These outcomes demonstrate that
contact lenses are a viable option
for managing aphakia—and rushing
into IOL implantation is not always
the right answer for patients who
are less than ideal candidates.
CHOOSING A LENS
Silicone elastomer soft contact
lenses are commonly used in the
early treatment of aphakia; however, they present challenges that
may be exacerbated when treating
the pediatric population: (1) while
highly permeable to oxygen, they
are prone to surface deposits, (2)
limited power and fitting parameters can make it difficult to properly
manage a patient and (3) financial
costs associated with contact lens
replacement, either due to power
changes or lens loss, can result in
poor compliance and follow up.
Gas permeable (GP) lenses are a
great resource for managing aphakic
infants. Due to infants’ small corneal diameter and narrow lid fissures,
they can easily tuck underneath the
taut lids and stay in place.5 They
are available in a wide range of
prescriptions and can be custom-
34 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
Photo: Viola Kanevsky, OD
A
lthough it may not
seem common, the
prevalence of congenital cataracts ranges
from one to 15 per
10,000 children.1 Approximately
one-third of congenital cataracts
are inherited, while the remaining
causes are associated with in utero
drug reactions, systemic diseases
such as rubella and measles or
idiopathic.1 In addition to obstructing vision, congenital cataracts may
cause other complications including
pediatric glaucoma and strabismus.2
For at-risk patients, cataract surgery
is indicated; however, there is some
uncertainty regarding the best age to
perform the surgery. Generally, cataract extraction should be performed
around six weeks of age for unilateral cataracts and between six and
eight weeks for bilateral cataracts
with a one- to two-week period
between surgeries for each eye.3
Post cataract surgery, eye care
providers face the challenge of finding the proper refractive correction
to reduce the risk of amblyopia.
If sufficient capsular support is
present, intraocular lens (IOL)
implantation can be performed
once the patient is two years of
This well-centered GP lens shows
good apical alignment.
ized to the desired power and base
curve. They are durable and simple
to handle, often making it easier on
parents to insert and remove.
Although GP lenses provide the
least incidence for microbial keratitis, lens loss and ocular irritation
tend to be the most common issues
with this lens material.5,6
FITTING GPs FOR APHAKIA
Because most patients are initially
examined under anesthesia, corneal
measurements, keratometry values
and a refraction by retinoscopy
should be available prior to the
contact lens fitting appointment.
When fitting a patient in GP lenses,
clinicians should select a base curve
that is 1mm to 1.5mm steeper than
the flattest keratometry reading—a value based off the Infantile
Aphakia Treatment Study Protocol.8
Evaluating the fluorescein pattern
may lead to a change in base curve.
The overall lens diameter is usually
10mm or larger, although this can
vary depending on the patient’s
corneal diameter. The optimal fitting
lens displays a well centered alignment fit, with adequate edge clearance evidenced by an approximately
1mm band of fluorescein around
the lens edge.7 Topical anesthetics
to facilitate the contact lens fitting
evaluation, and during insertion
and removal training are typically
not required, because the child’s
fear is usually what makes these fits
difficult, not lens awareness.8
Once clinicians determine the
appropriate cornea-to-lens relationship, they can refine lens powers by
retinoscopy over the diagnostic lens.
In children under the age of two, 2D
to 3D of additional plus are added
to the lens to provide clear near
vision. Spare lenses should be pro-
vided in the event the contact lens
is lost to allow continued optical
correction to prevent amblyopia.8
CORRECTION AFTER TWO
Bifocal lenses are prescribed for the
child around age two, when the
added power of over-plussed lenses
begins to interfere with distance
viewing.8 Often, the GP lens is made
for full distance correction, and
the clinician then prescribes over-
lay bifocal spectacles with a +3.00
add power. Choosing bilateral or
unilateral bifocals is often left to the
clinician’s preference.
Generally speaking, if a patient
has unilateral aphakia, unilateral
bifocals are prescribed to allow the
phakic eye to accommodate freely
without creating unnecessary blur.
Progressive lenses can also be used if
the patient has bilateral aphakia.
(Continued on page 37)
CASE EXAMPLE
A two-month-old female patient was referred for a
contact lens evaluation following cataract extraction.
The patient presented wearing a Silsoft Super Plus
(Bausch + Lomb) 7.5 base curve, 11.3 overall diameter
(OAD) and +32.00D power—inserted by her cataract
surgeon for extended wear until she could be seen by
a specialty contact lens fitting optometrist.
At the first contact lens visit, retinoscopy showed
a +4.50D over-refraction. Examining the contact lens
fit using a 20D lens and transilluminator revealed
adequate centration, good movement and full corneal
coverage. Although an adequate fit, the Silsoft
contact lens has a maximum power of +32.00D, and a
GP contact lens was considered in the near future.
The parents were trained on insertion and removal
of the soft contact lens and advised to remove
the lens each night and clean it with a hydrogen
peroxide solution. An online video on insertion and
removal was recommended in case at-home review
was necessary. A multipurpose solution safe for
immediate contact with the eye was also dispensed
in the event the lens required immediate cleaning.
RECHECK
Two weeks later, during the recheck, retinoscopy
revealed an over-refraction of +3.75D. Examination
demonstrated good centration and movement of the
contact lens. Because the patient needed additional
plus power, a GP contact lens fitting was initiated.
The initial lens trialed was a 6.75 base curve, 8.5
OAD and +20.00D. Examination using a blue light
demonstrated a steep fit with bubbles and poor
centration. Flatter diagnostic lenses were trialed
until an apical alignment or minimal apical clearance
pattern was evident. Over-refraction was completed
and the new power was determined by adding an
additional +3D to ensure the patient was left 3D
myopic. A larger OAD lens was ordered, along with a
larger optic zone to maintain alignment pattern and
improve centration. The new lens parameters were
7.34 base curve, 9.20 OAD and +40.00D.
DISPENSING
On the dispensing visit, the lens was slightly too
steep and was decentering temporally. A few
modifications to the base curve assisted with
centration and overall fit. The parents were trained
on GP insertion and removal, and hydrogen peroxide
solution was recommended for lens care. Once
the lens was finalized, a spare lens was ordered
and dispensed as well. The patient was followed
every one to two months initially, then by threemonth intervals once lens changes became less
frequent. She was routinely seen by the pediatric
ophthalmologist and prescribed aggressive occlusive
therapy for amblyopia management.
At age two, the patient returned for a contact lens
evaluation. The lens power was modified to correct
for distance, and overlay polycarbonate unilateral
bifocals were prescribed for full-time wear. The
patient was seen every three months until age three,
then followed every three to six months.
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
35
Pharma Science & Practice
By Elyse L. Chaglasian, OD, and Tammy Than, MS, OD
Corneal Collagen Crosslinking:
Not Just for Adults
Treatment plans for pediatric patients with keratoconus may get an upgrade soon with
this newly approved technology.
C
orneal collagen crosslinking (CXL) is quickly becoming a first-line
approach for managing
progressive keratoconus in adults, accelerated by the
FDA’s approval of the Avedro system in early 2016 for patients older
than 14. CXL photosensitizes the
collagen of the corneal stroma and
increases its biomechanical rigidity,
thus halting or possibly reversing
the progression of keratoconus.
But adults aren’t the only ones in
need of treatment. A retrospective
study to determine the incidence
and presentation of pediatric keratoconus (younger than 14) found
that over a five-year period, 541
of 2,972 patients were diagnosed
with keratoconus—an incidence of
0.53%, representing 2.96% of all
cases diagnosed during that time.1
In comparison, the incidence in the
adult population is 3.78%.1
Because studies evaluating the
efficacy of CXL have focused on
adults, the incidence and severity of
keratoconus in children is poorly
understood, as is the potential role
for CXL in the pediatric population.
PEDIATRIC CHALLENGES
Treating children presents a number
of unique challenges. Most management strategies successful with
adults, such as specialty contact
lenses, are less so with children,
given complications such as difficulty with wear and care compliance
and poor outcomes with corneal
transplantation.2,3 Keratoconus in
children is often associated with
vernal keratoconjunctivitis and eye
rubbing, which can lead to hydrops,
so care must be taken to quell the
surface inflammation with topical
anti-allergy and steroid drops.4
Additionally, keratoconus in
children tends to be more severe at
initial presentation and progresses
more quickly than in newly diagnosed adult patients.5 A retrospective study of 49 patients younger
than 15 and 167 older than 27 with
keratoconus at initial presentation
found the disease was more severe
at diagnosis in subjects in the first
group: 27.8% were already at
stage 4 using Krumeich’s classification, as compared with 7.8% of
adult subjects.5 Stage 4 includes
non-measurable refraction; mean
central keratometry readings >55
diopters; central corneal scarring
and a minimum corneal thickness
of 200µm.The younger subjects also
had more advanced slit lamp signs
and keratometry readings.5
CXL IN KIDS: THE LITERATURE
Given the difficulties in fitting the
pediatric population with contact
lenses and the greater propensity for
full thickness corneal graft rejection,
CXL could be the answer, as preliminary studies indicate it stabilizes
the disease process and reduces the
need for keratoplasties. So far, three
studies have evaluated the efficacy
of CXL—with a standard epi-off
treatment—and the progression of
keratoconus in the pediatric population. Patients were pretreated with
36 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
topical anesthesia and removal of
the corneal epithelium, followed
by a soak of 0.1% riboflavin/20%
dextran solution (varied from
10 to 30 minutes) and then 30
minutes of UVA irradiation (six
times for five minutes each), with
instillation of riboflavin/dextran
every five minutes. Post-procedure,
antibiotic and cycloplegic drops
were instilled, along with a bandage contact lens. Some children
required general anesthesia, while
others required only topical.6-8
One study evaluated patients age
10 to18, divided into two groups by
corneal thickness: less than 450µm
and greater than 450µm.6 At 36
months post-CXL treatment, no adverse events were reported and both
groups showed an improvement in
uncorrected Snellen visual acuity
(VA), topography and coma. There
was a faster functional response in
patients with thinner corneas.
Another study evaluated the refractive, topographic, aberrometric
and tomographic results in patients
ages nine to 18 for up to two years.7
There was a slow but continuous
improvement of most of the indices
up to 24 months after surgery, with
no adverse events noted.
Finally, a study evaluating patients age nine to 19 for progression
of keratoconus and the efficacy of
CXL up to three years postoperatively found 88% exhibited progression (an increase in the maximum
keratometry of at least 1.00D over
a one-year period).7 The researchers
analyzed maximum keratometry
A Fleischer ring, as seen in some
keratoconus patients.
values, corrected distance VA, corneal thickness and the keratoconic
index. They found the maximum
keratometry value was reduced
by three months and remained for
up to 24 months. However, at 24
months, it began to show progression, suggesting pediatric corneas
do not allow for long-term improvement, although the best-corrected
distance VA continued to be better
than pre-CXL.8
One study performed transepithelial (epi-on) CXL on 13 eyes in
patients ages eight to 18.9 While the
procedure was safe, well tolerated
and the corrected distance visual
acuity was improved at 18 months
of follow-up, it did not halt the progression of keratoconus as seen with
the standard epi-off treatment.9
T
his research suggests keratoconus in pediatric patients is more
severe and progresses more quickly
than in adults, and standard CXL is
safe and effective, although perhaps
more transient, in patients younger
than 18.
More studies with longer follow
up are needed, but it appears CXL
can be seriously considered in our
treatment of keratoconus for patients as young as 14.
RCCL
1. el-Khory S, Abdelmassih Y, Hamade A, et al.
Pediatric keratoconus in a tertiary referral center:
incidence, presentation, risk factors and treatment. J
refract Surg. 2016;32(8):534-41.
2. Vanathi M, Panda V, Vengayil S, et al. Pediatric
keratoplasty. Surv Ophthalmol. 2009;54:245-71.
3. Lowe MT, Keane MC, Coster DJ, Williams KA. The
outcome of corneal transplantation in infants, children and adolescents. Ophthalmology. 2011;118:492-7.
4. Rehaney U, Reumelt S. Corneal hydrops associated with vernal keratoconjunctivitis as a presenting
sign of keratoconus in children. Ophthalmology.
1995:1021(12):2046-9.
5. Leoni-Mesplie S, Moortemousque B, Touboul
D, et al. Scalability and severity of keratoconus in
children. Am J Ophthalmol. 2012;154:56-62.
6. Caporossi A, Mazzotta C, Baiocchi S, et al. Riboflavin-UVA-induced corneal collagen crosslinking in
pediatric patients. Cornea. 2012;31(3):227-31.
7. Vinciguerra P, Albé E, Frueh BE, et al. Two-year
corneal cross-linking results in patients younger
than 18 years with documented progressive keratoconus. Am J Ophthalmol. 2012 Sep;154(3):520-6.
8. Chatzis N, Hafezi F. Progression of keratoconus
and efficacy of pediatric corneal collagen crosslinking. J Refract Surg. 2012 Nov;28(11):753-8.
9. Buzzonetti L, Petrocelli G. Transepithelial corneal
cross-linking in pediatric patients: early results. J
Refract Surg. 2012 Nov;28(11):763-7.
THE GP EXPERTS: TREATING INFANTILE APHAKIA: THINK GPS
(Continued from page 35)
FOLLOW UP
Close follow up is imperative for
success with GP contact lenses in
managing infantile aphakia. The
corneal radius and diameter rapidly
change during infancy, resulting in
several lens changes throughout the
first year.
Questions regarding photophobia, irritation, excessive blinking,
redness or discharge should to be
addressed at each visit. Contact lens
wearing time should be gradually
increased starting with a few hours
initially until wear time during all
waking hours is achieved.
N
oncompliance is one of the
biggest problems with aphakic
management. Loss of contact lenses,
poor fit and cost of lenses are some
reasons for noncompliance in pediatric patients.
Although managing aphakia can
be challenging, clinicians should
consider GP lenses due to their
continued success in visual rehabilitation.
RCCL
1. Foster A, Gilbert C, Rahi J. Epidemiology of cataract in childhood: a global perspective. J Cataract
Refract Surg. 1997;23 Suppl 1:601-604.
2. Lim ME, Buckley EG, Prakalapakorn SG. Update
on congenital cataract surgery management. Curr
Opin Ophthalmol. Jan 2017;28(1):87-92.
3. Lambert SR. The timing of surgery for congenital
cataracts: Minimizing the risk of glaucoma following
cataract surgery while optimizing the visual outcome. Journal of AAPOS : the official publication of
the American Association for Pediatric Ophthalmology and Strabismus. Jun 2016;20(3):191-192.
4. Russell B, DuBois L, Lynn M, Ward MA, Lambert
SR, Infant Aphakia Treatment Study G. The Infant
Aphakia Treatment Study Contact Lens Experience
to Age of 5 Years. Eye Contact Lens. Jul 27 2016.
5. Baradaran-Rafii A, Shirzadeh E, Eslani M, Akbari
M. Optical correction of aphakia in children. Journal
of ophthalmic & vision research. Jan 2014;9(1):71-82.
6. Liesegang TJ. Contact lens-related microbial keratitis: Part I: Epidemiology. Cornea. Mar
1997;16(2):125-131.
7. Amos CF, Lambert SR, Ward MA. Rigid gas permeable contact lens correction of aphakia following
congenital cataract removal during infancy. Journal
of pediatric ophthalmology and strabismus. Jul-Aug
1992;29(4):243-245.
8. Wilson ME, Rupal H. Trivedi , Suresh K. Pandey.
Pediatric cataract surgery: techniques, complications, and management. Lippincott Williams &
Wilkins; 2005.
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
37
Corneal Consult
By Aaron Bronner, OD
A New Year, a New Look at the Cornea
Learning to recognize the processes that govern corneal health and function will allow
you to gain a deeper understanding of pathologies and their treatments.
I
magine a new patient presenting
to your office with a painful eye
and profoundly reduced acuity.
There is no infiltrate, but the
cornea appears hazy, perhaps
edematous, though it’s difficult to
tell. What would your working
diagnosis be? What happens to your
diagnosis if the patient is an extended wear contact lens user? What if
they qualify their pain as superficial,
or deep? What if they had a corneal
transplant to this eye six months,
or even 20 years, ago? What if they
had a transplant, but to the fellow
eye? Finally, what happens if your
original treatment fails?
These situations come up periodically in my clinic and each subtle
variation in history should generate
a separate primary differential and
treatment. Transitioning smoothly
among these differentials, being able
to separate the important clinical
finding or historic element from
the red herring, is key to effectively
managing these patients.
Welcome to my first edition of
Corneal Consult, a column in which
I hope to explore the diagnostic and
therapeutic challenges we face when
dealing with corneal pathology and
provide real-world, clinically useful
practice pearls each edition.
In my first column, I’d like to
introduce myself and share my
background, training and current
clinic environment, as well my
future goals for this column.
MY CLINICAL WORLD
Most of you (statistically, it’s closer
to “all of you”) don’t know me.
I’m Aaron Bronner, an optometrist
working in the Kennewick, Wash.,
office for Pacific Cataract and Laser
Institute (PCLI), a multicenter, comanagement group.
PCLI was one of the first comanagement groups in the nation and
was one of the earliest to perform
Medicare-approved outpatient cataract surgery. Our mission statement
is to provide the best care possible
to our optometric referral network,
and we deal exclusively with referral-based care.
At my facility, beyond the standard menu of cataract and refractive
surgeries, we provide surgical and
medical corneal care for a large part
of Eastern Washington and Oregon.
In addition to the 100 or so great
ODs I work with indirectly through
comanagement, I work directly
with two skilled optometrists, Brian
Johnson and Bruce Flint, and five
gifted, gracious ophthalmologists,
Jim Guzek, Jason Leng, Loren Seery,
Ron Sugiyama and Marshall Ford—
they all bear mentioning because
they are, unwittingly, contributors
to this column. (Thanks, guys!)
At PCLI, ODs maintain some
level of involvement at all levels of
perioperative and medical care—
even in very complex medical cases,
we stay involved with clinical decision making and will collaborate
with our MDs rather than simply
referring to our MDs for consultative services. It’s an exciting, sometimes stressful, way to practice and
provides a phenomenal opportunity
to continue learning. I hope to
draw on this experience and make
this column as useful to the readers
as possible. In addition to clinical
responsibilities, I also teach residents
though the Jonathan Wainwright
38 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
VAMC clinic in Walla Walla, Wash.,
and you’ll be reading about them
from time to time.
MY INTERESTS
I became interested in both corneal care and teaching during my
residency, which was performed
at Davis Duehr Dean Eye Care
in Madison, Wis., about 10 years
ago. During my residency, I rotated
through some amazing ophthalmologic clinics; I spent about half of
my time in the cornea clinic of Chris
Croasdale, MD. During this time,
I realized that, despite my training,
I was a fish out of water with complex surgical or severe corneal disease cases—they were so far outside
my experience I couldn’t formulate
effective diagnoses or treatments.
After taking a mental accounting
of how and why I was struggling,
my initial step to remedying the situation was to observe Dr. Croasdale’s
approach to clinical problems. First
of all, he just knew way more than
me. Given where I was in my career
path, and where he was in his,
there was nothing I could do about
this gap—research and continued
learning were the only tools I could
use to help narrow that difference to
a more acceptable margin.
But there was one area I could
address immediately: the stark
difference in how we mentally
approached cases. He employed
what I’d call a process-driven approach, while I, at the time, used a
results-driven approach.
MY FIRST PRACTICE SHIFT
My results-driven approach to
clinical cases was perfected by four
years of optometry school and its
incumbent testing. I had learned to
assess each finding not as a process
taking place within the eye, but only
as a piece of a puzzle that, once put
together, led to a diagnosis—finding
X is tied to diagnosis Y. In essence,
I simply memorized a large number of findings and their respective
diagnoses, and if a case I encountered showed enough associated
findings, I would have a diagnosis. At its root, this results-driven
approach was not based on any
actual understanding of pathologic
and physiologic processes, but on
memorization. Perhaps this was less
elegant, clinically, than an in-depth
understanding of pathophysiology,
but it was effective much of the time
and was adequate during school.
Dr. Croasdale, however, approached cases quite differently.
Rather than focusing exclusively
on a finding tied to a diagnosis, his
process-driven strategy emphasized
what pathologic and physiologic
process the finding represented
within the eye.
This was a revolutionary discovery for me. By shifting from my own
memorization-based approach to
Dr. Croasdale’s process-driven approach, I focused on understanding
the processes taking place and realized a deeper understanding of the
pathology and the appropriate diagnoses, which was particularly useful
for cases that weren’t textbook.
Though both of these approaches
work when a clinician is familiar
with the underlying diagnosis, the
results-driven approach breaks
down immediately when faced with
an unfamiliar constellation of findings on non-textbook presentations.
The Bronner family—Aaron and
Becky, Zoë and Liam—enjoying
Disneyland at Academy 2016.
With no diagnosis tethered to these
unfamiliar findings, an accurate
diagnosis is impossible; a finding
without a linked diagnosis becomes
meaningless or, worse, confusing.
Unusual cases demand clinicians
interpret a series of often unfamiliar
findings and assimilate them into
a useful differential based on the
processes taking place in the eye.
Once I realized this flaw, I sought,
during my residency (and during my
career), to better understand the disease processes encountered in clinical practice. The tricky thing with
learning in a postgraduate setting
is that you never know what you
didn’t know until you know it. For
you to realize a gap in your knowledge base, someone who knows
more has to point it out. I’ve tried
to get around this limitation with
literature research, practicing in a
challenging clinical setting where I
am routinely exposed to new things
and, most importantly, collaborating with more experienced ODs and
MDs (in addition to those already
named, I’d be remiss if I didn’t
mention Walt Whitley, OD, Doug
Devries, OD, James Adamek, OD,
and Jeff Urness, OD, as professionals from whom I’ve directly drawn a
lot of information).
MY COLUMN GOALS
I have two goals for this column.
First, I hope to share some of these
diagnostic and therapeutic associations and hopefully help you, too,
realize a deeper understanding of
what is actually taking place in corneal pathologies and their respective
treatments. I believe understanding
mechanisms involved will encourage a process-driven approach and
benefit you in clinic.
Second, I’d like to revisit some of
the vast corneal findings we learn
about in our training. The nature of
our optometric education requires
us to assimilate so much information so rapidly that it becomes
impossible to assign the appropriate
context to register all of it in our
long-term memory. I hope to re-explore some of these findings and
help assign more clinical relevance
to them to allow better recall.
It takes a certain amount of ego
to think you can offer to teach a
similarly credentialed group of
colleagues, and academic lecturing
is not my intention in these pages.
A smart person once told me that
“study is a means to an end, it isn’t
the end itself.” As ODs, academic
knowledge supports clinical practice, not the other way around. So
while occasionally the column may
delve into academics, I will always
attempt to tie it back into a concept
with clinical value. Each of the concepts I will discuss started as something I was initially unaware of, and
upon learning the concept, felt it
helped shape my clinical thinking.
I enjoy presenting information in
a new manner, and I hope you enjoy
the column and learn as much from
my experiences as I have. Cheers!
RCCL
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
39
Practice Progress
By Mile Brujic, OD, and David Kading, OD
Daily Disposables: Effective
From Allergy to Astigmatism
More patients than you might think can benefit from this contact lens modality.
D
aily disposable lenses
have revolutionized our
patient care. Not only
do our current contact
lens wearers benefit
from daily disposable lens, but also
those new to contact lenses or those
who are interested in wearing them
on a part-time basis. Other than daily replacement, there are a number
of other indications when dailies
may be appropriate, including:
Solution sensitivity. Individuals
wearing a frequent replacement lens
not approved for extended wear require multipurpose disinfecting solutions to care for their lenses. Some
individuals may experience solution
sensitivities over time.1,2,3 Removing
care solutions by prescribing daily
disposable lenses will often alleviate
the signs and symptoms associated
with solution sensitivity.
Compliance issues. Research
demonstrates a clear link between
noncompliance with manufacturers’ recommended replacement
frequency (a common problem with
frequent replacement lens wearers)
and a degradation in contact lens
comfort levels.4,5
In addition, studies show most
individuals do not clean and replace
their storage solution appropriately.6-8 Daily disposables help avoid
these challenges, as cleaning and
storage are not required.9 Further, at
least one study shows daily disposable lens wearers are the most
compliant of all lens wearers.10
Medical history. Certain medical
conditions such as seasonal allergic
conjunctivitis warrant consideration for daily disposable lens
wear.11 After treating the underlying
condition, daily disposable lenses
are a beneficial option, considering
allergens and other immune complexes commonly seen in the tears
of allergy sufferers will be disposed
of at the end of the day.12,13
Giant papillary conjunctivitis
(GPC), in particular, is a much more
chronic form of allergy that usually
requires more aggressive medical
therapy. GPC is typically caused by
excessive deposition on contact lens
surfaces, causing an immunological
response of the conjunctival tissue
and leading to “giant papillae.”14,15
These cases often warrant temporary discontinuation of contact
lenses and topical corticosteroid
therapy.16 Although lens wear
can continue after the response is
controlled, the cleanest surface will
ultimately provide the best patient
outcomes and the least likelihood of
recurrence.
NEW TECHNOLOGIES
With so many advantages to daily
disposable lens wear, it is no wonder that we are more frequently
reaching for this modality with
our contact lens wearers. Limited
parameter availability has traditionally hindered our ability to fit a
number of our contact lens wearers
for daily disposable lenses. But, in
the last several years, contact lens
manufacturers have introduced a
variety of technologies that allow
our patients to have an enhanced
daily disposable lens wearing experience through new materials and the
availability of multifocal and toric
contact lens options.
40 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
The availability of toric contact
lens options in a daily disposable
modality is critical when fitting the
contact lens neophyte, including
pediatric patients. One study disproved the preconceived notion that
patients younger than 13 cannot
wear contact lenses.17 The advent of
daily disposable astigmatic designs
offers more individuals the comfort
and convenience our spherical lens
wearers currently enjoy.
ASTIGMATISM
Healthy ocular findings, high motivation and maturity are the markers
of a good pediatric candidate for
astigmatic correction though contact lenses. These daily disposable
astigmatism correcting contact lenses are well suited for any individuals
requiring astigmatic correction,
especially children:
• 1-Day Acuvue Moist for
Astigmatism (Johnson & Johnson
Vision Care). This lens material is
the same technology in the 1-Day
Acuvue Moist spherical lens: etafilcon A and 58% water.18 It provides
stability through a blink stabilized
design based on a dual thin zone,
Fig. 1. Small mark located at the
six o’clock position as seen in most
lenses for astigmatism.
along with additional stabilization
factors that interact with both the
upper and lower lid. The orientation markers are located at the six
and 12 o’clock position (Figure 1).
Notably, there is no fear of placing
this lens upside down on the eye;
either orientation will feel identical
to the patient and provide the same
visual experience.
• Biotrue OneDay for
Astigmatism (Bausch + Lomb). This
lens is made of the same material
as its spherical predecessor, the
Biotrue OneDay lens: nesofilcon A
and 78% water content. It contains
polyvinylpyrrolidone (PVP) that facilitates the high water content and
poloxamer 407, which helps retain
moisture and prevent dehydration
on the lens. The lens is stabilized on
the eye with a peri-ballast design
and has a light blue visibility tint.
The orientation marker on this lens
is located at the six o’clock position
and is easily seen at the slit lamp. A
fine laser-etched mark indicates the
axis of the lens.19
• Clariti 1 Day Toric (Cooper
Vision): This lens is a silicone hydrogel daily disposable made of somofilcon A and is 56% water. The
material is the same as that in the
Clariti 1 Day sphere and multifocal
lens.20 The modulus of the lens is
relatively low for a silicone hydrogel
lens, which makes it feel similar to
a hydrogel when handling the it.
The stability of the lens is created
through a prism ballast design in addition to a back surface toric profile.
The orientation marker is located at
the six o’clock position, making it
easily visible at the slit lamp.
• Dailies AquaComfort Plus
Toric (Alcon). This lens is made of
nelfilcon A and is 69% water, the
same as the Dailies AquaComfort
Plus sphere and multifocal lenses.
This lens contains hydroxypropyl
methylcellulose, which aids in initial
comfort. Additionally, moisturizing
agents polyvinyl alcohol and polyethylene glycol are released from
the lens throughout the day.21 The
lens is stabilized through a dual thin
zone along with a back surface toric
design with scribe marks located at
the three and nine o’clock positions.
There is also an “OK” inversion
indicator on the lens (Figure 2). The
back of the “K,” located 90 degrees
from the horizontal meridian, can
be used as an indicator of rotation.
W
ith the growing number of
daily disposable toric lens options, we can provide more patients
than ever with the benefits they
bring, especially for new contact
lens wearers and children. Make
use of these ever-improving options
when appropriate to offer your
pediatric patients the benefits of a
daily disposable lens.
RCCL
1. Kalsow CM, Reindel WT, Merchea MM, et al. Tear
cytokine response to multipurpose solutions for
contact lenses. Clin Ophthalmol. 2013;(7):1291-302.
2. Choy CK, Cho P, Boost MV. Cytotoxicity and effects on metabolism of contact lens care solutions
on human corneal epithelium cells. Clin Exp Optom.
2012 Mar;95(2):198-206.
3. Epstein AB. Contact lens care products effect
on corneal sensitivity and patient comfort. Eye
Contact Lens. 2006 May;32(3):128-32.
4. Ramamoorthy P, Nichols JJ. Compliance factors
associated with contact lens-related dry eye. Eye
Contact Lens. 2014 Jan;40(1):17-22.
5. Dumbleton K, Woods C, Jones L, et al. Comfort
and vision with silicone hydrogel lenses: effect of
compliance. Optom Vis Sci. 2010 Jun;87(6):421-5.
6. Robertson DM, Cavanagh HD. Non-compliance with contact lens wear and care practices:
a comparative analysis. Optom Vis Sci. 2011
Dec;88(12):1402-8.
7. Dumbleton KA, Spafford MM, Sivak A, Jones LW.
Exploring compliance: a mixed-methods study of
contact lens wearer perspectives. Optom Vis Sci.
2013 Aug;90(8):898-908.
8. Morgan PB, Efron N, Toshida H, Nichols JJ. An
Fig. 2. ‘OK’ marking along with three
and nine o’clock markings with the
Dailies AquaComfort Plus Toric Lens.
international analysis of contact lens compliance.
Cont Lens Anterior Eye. 2011 Oct;34(5):223-8.
9. Dumbleton K, Richter D, Bergenske P, Jones LW.
Compliance with lens replacement and the interval
between eye examinations. Optom Vis Sci. 2013
Apr;90(4):351-8.
10. Dumbleton K, Richter D, Woods C, et al.
Compliance with contact lens replacement in
Canada and the United States. Optom Vis Sci. 2010
Feb;87(2):131-9.
11. Siddique M, Manzouri B, Flynn TH, Ono SJ.
Allergy and contact lenses. Chem Immunol Allergy.
2007;92:166-75.
12. Nichols KK, Morris S, Gaddie IB, Evans D.
Epinastine 0.05% ophthalmic solution in contact
lens-wearing subjects with a history of allergic conjunctivitis. Eye Contact Lens. 2009 Jan;35(1):26-31.
13. Brodsky M, Berger WE, Butrus S, et al. Evaluation of comfort using olopatadine hydrochloride
0.1% ophthalmic solution in the treatment of allergic
conjunctivitis in contact lens wearers compared to
placebo using the conjunctival allergen-challenge
model. Eye Contact Lens. 2003 Apr;29(2):113-6.
14. Solomon A. Allergic manifestations of contact
lens wearing. Curr Opin Allergy Clin Immunol. 2016
Oct;16(5):492-7.
15. Elhers WH, Donshik PC. Giant papillary conjunctivitis. Curr Opin Allergy Clin Immunol. 2008
Oct;8(5):445-9.
16. Bartlett JD, Howes JF, Ghormley NR, et al.
Safety and efficacy of loteprednol etabonate for
treatment of papillae in contact lens-associated
giant papillary conjunctivitis. Curr Eye Res. 1993
Apr;12(4):313-21.
17. Walline JJ, Jones LA, Rah MJ, et al. Contact
Lenses in Pediatrics (CLIP) Study: chair time and
ocular health. Optom Vis Sci. 2007 Sep;84(9):896902.
18. Acuvue. Available at www.acuvueprofessional.
com/product/moist-astigmatism. Accessed January 4, 2017.
19. Bausch + Lomb. BioTrue oneday for astigmatism. Available at www.bausch.com/our-products/contact-lenses/lenses-for-astigmatism/
biotrue-oneday-for-astigmatism. Accessed January
4, 2017.
20. Cooper Vision. Clariti 1 day toric. Available
at http://coopervision.com/contact-lenses/clariti-1-day-toric. Accessed January 4, 2017.
21. Alcon. Dailies aquacomfort plus contact lenses.
Available at www.myalcon.com/products/contact-lenses/dailies/aquacomfort-plus-technology.
shtml. Accessed January 6, 2017.
REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
41
The Big Picture
By Christine W. Sindt, OD
Retained PK Sutures
This graft patient showed suture fragments on follow-up. Is it a cause for concern?
S
hown here is a 26-yearold female patient who
previously underwent
penetrating keratoplasty
(PK) for Acanthamoeba
keratitis (AK) unresponsive to
medical therapy. The graft size
is larger than average due to the
advanced state of the AK ulcer and
the need for sufficient border zone
of healthy, unaffected tissue. She
is two years out from the transplant with all her corneal sutures
removed, although the broken
suture remnants visible here will
permanently remain in her cornea.
Healing response to graft placement
is positive, with no evidence of rejection or failure. The corneal scarring and suture fragments will not
affect vision. However, the retained
suture fragments could provide
42 REVIEW OF CORNEA & CONTACT LENSES | JANUARY/FEBRUARY 2017
a vector for microbial infection,
requiring heightened vigilance from
both the clinician and patient.
RCCL
CALL FOR ENTRIES: Do you have
great clinical images of fascinating
cases you would like to share with
your colleagues on this page and
online? Send large, high resolution
photos (corneal disease or contact
lens wear only) and a brief case
description to: [email protected].
RCCL0217_Xcel.indd 1
1/26/17 2:54 PM
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1/30/17 11:28 AM