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AMO Resident Most Challenging Contact Lens Case
Catherine Pannebaker, O.D.
INTRODUCTION
Keratoconus is an asymmetric condition of corneal ectasia and thinning with
onset usually in early teens to early twenties, with an incidence of about 1/2000 [1].
Patients can be markedly visually impaired with high amounts of irregular astigmatism
and myopia.
Classic objective signs seen by biomicroscopy include stromal thinning, central
scarring, vertical lines in the posterior cornea (Vogt’s striae), and prominent corneal
nerves; quite often a brownish or olive green colored ring of iron deposition (Fleischer’s
ring) is seen at the base of the “cone” or apex of the protrusion. Additional signs include
a bowing outward of the inferior lid in downgaze (Munson’s sign) and steepened
keratometry or topography readings.
In some advanced cases of keratoconus, breaks in the posterior cornea can occur.
This causes an influx of aqueous humor, and leads to an acute and painful onset of
corneal edema. These episodes of corneal hydrops usually result in scarring. Fibrotic
scarring near the visual axis and apex of cone are also evident in many patients even in
the absence of hydrops.
Although improved with pinhole, the best corrected visual acuity in keratoconus
patients is often reduced with spectacle correction; therefore, most patients are managed
with rigid gas permeable contact lenses in a wide range of specifications. Some patients
may require penetrating keratoplasty if contact lenses are no longer a management
option.
Keratoconus is historically defined as a non-inflammatory condition. The exact
etiology is unknown, however, recent literature suggests that inflammation molecules
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Catherine Pannebaker, O.D.
and abnormal levels of enzymes are present in patients with keratoconus [2,3]. Other
research indicates that keratoconus may also have genetic components [4]. Frequent
associations include history of allergies, atopy (asthma, hay fever, eczema), eye rubbing,
eye injuries, rigid contact lens wear, and family history of keratoconus [5]. Curiously,
the condition seems to cease progression with increasing age [6,7].
The sections to follow will summarize literature regarding studies on related
proteins in corneal tissues and tears, as well as possible genetic and inflammatory aspects
involved in the etiology and progression of keratoconus.
Tear Proteins
Extensive tear protein work performed by Souza et al has resulted in the
identification of 491 proteins, both extracellular and intracellular, the latter of which may
result from cell death in the epithelium of the cornea [8]. Many proteins are contained in
the aqueous layer of the tears and are secreted by the lacrimal and accessory glands. The
majority of these proteins in the normal tear film consist of lysozyme, lactoferrin,
secretory immunoglobulin A, serum albumin, lipocalin, and lipophilin [9]. In addition,
these proteins are in a relatively high concentration (8 ųg/ųL), and easily accessed in tear
collection methods, making the tear film very promising for extensive protein analysis
via such methods as enzyme-linked immunosorbent assay (ELISA), mass spectrometry
and others [8]. The study of proteins, or proteomics, is valuable in identification of
molecular markers involved in such processes as wound healing, the immune response,
inflammation, and oxidative stress, or damage to tissues resulting from the inability to
process reactive oxygen species.
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AMO Resident Most Challenging Contact Lens Case
Catherine Pannebaker, O.D.
Tissue and Ocular Surface Disorder
Teng used electron microscopy in the 1960’s to investigate the pathologic
changes in the corneal tissue of
keratoconus patients [10].
He confirmed the
decomposition of the basement and Bowman’s membranes, and stated that the result of
enzyme activities could affect collagen and nerve fibers along with Descemet’s
membrane.
Additional studies by Jongebloed and Sawaguchi revealed not only a lack of
replacement of epithelial cells leading to holes exposing Bowman’s membrane in some
areas, but also an “accelerated aging process” in the epithelium [11-14].
Murat Dogru et al studied changes in the ocular surface in terms of corneal
staining, goblet cell density, and squamous metaplasia using standard Schirmer testing
and impression cytology; these tests were performed on mild to severe keratoconus
patients who had no history of contact lens wear, ocular surgery or other active systemic
or eye conditions [14].
They found that nearly 46.6% of the eyes had punctate
keratopathy and 70.6% had a tear breakup time <10 seconds; squamous metaplasia was
an average of 10 times greater in the keratoconus eyes verses control eyes, and goblet cell
density was half that of control eyes [14]. The significance of the squamous metaplasia is
that an actual transformation of tissue has occurred. Goblet cells are important in
producing mucins: glycoprotein secretions known to create a hydrophilic ocular surface
and therefore aid in tear film stability [15-16]. An interesting finding in Dogru’s study
was that Schirmer testing revealed no significant differences between the keratoconus
eyes and control eyes, suggesting an absence of aqueous-deficient dry eyes [14]. Dogru
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suggested the possibility of new approaches in therapies for keratoconus patients. These
therapies include topical retinoids, which have been shown to aid in producing basement
membrane components, and topical 15-(S)-hydroxyeicosatetraenoic acid for increasing
mucin secretions [12]. This study and others to be discussed may be suggestive of tissue
and tear function abnormalities in keratoconus.
Genetic Studies
Numerous genetic studies have been performed with the hope of discovering a
gene that is solely responsible for keratoconus. Noting that keratoconus has systemic and
familial associations, genetics most likely plays a role in the etiology [17]. Furthermore,
the variability displayed in families, the asymmetry with which the eyes are affected, and
discordance between mono- and dizygotic twins supports a genetic component [18-20].
There are a few cases of monozygotic twins in which one had clinical signs of
keratoconus, and the other lacked any signs – even with topography – owing evidence
that environmental aspects play a role as well [19].
Both dominant and recessive
inheritance patterns have been seen in families, and the variable expression of
keratoconus remains puzzling [21-23]. However, the development of corneal topography
now enables a method of early detection in the condition, which further helps to clarify
pedigrees and prevalence in families as it is used to test family members and show
similarities in the cone presentation (e.g., central, inferior) [24,25].
Keratoconus has proven associations with Down syndrome (10-300 fold increase
in prevalence), Leber’s congenital amaurosis, atopy and connective tissue disorders; these
associations can be important in providing chromosomal information since these
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disorders have a defined genetic origin [26]. The most compelling systemic association
is with mitral valve prolapse, as Beardsley and Sharif found 44% and 58% prevalence in
their subjects respectively, possibly indicating a link with collagen abnormality [26-28].
Unfortunately, some genetic studies in the past used inconsistent methods, and
many were conducted mostly on caucasians [29-30].
Rabinowitz recently recruited
hispanic, black, and asian subjects in addition to whites and found some consistency in
linkage between whites and hispanics [17]. He found evidence of linkage to keratoconus
on chromosomes 4, 5, 9, 12, and 14 for whites “and/or all pedigrees”, and additionally
chromosome 17 for Hispanics only [17].
Specifically, Rabinowitz targeted three
candidate keratoconus genes from these chromosomes: lysyl oxidase, a gene responsible
for collagen cross-linking; cell death-inducing DEFA-like effector b, thought to be
involved in apoptosis; and gelsolin, a gene also associated with another corneal dystrophy
[17]. Although his study could only conclude that many loci are involved in keratoconus,
it was the first of its kind with a large sample size (351 subjects phenotyped) to identify
linkage in populations other than whites, and will most likely challenge other scientists to
recruit a variety of subpopulations [17]. In addition, Rabinowitz has shown linkage to
other chromosomes – 3, 13, 15, 16, 17, 20, and 21 (significant in trisomy 21), yet the
exact genetic cause for keratoconus is still not clear in that genes were not found at the
precise loci [31,32].
Although associated with polymorphous corneal dystrophy, the visual system
homeobox 1 gene (VISX1) has been widely speculated as a possible mutation involved in
keratoconus [33-35]. Aldave et al recently disproved this in a study of four specific
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mutations, showing that VSX1 gene mutations are not associated with the etiology of
keratoconus [35].
Udar et al recently studied superoxide dismutase 1 (SOD1) along with Christina
Kenney’s group as a possible candidate gene in keratoconus [32]. Superoxide dismutase
on chromosome 21 is an enzyme known to be involved in antioxidant activities by
reducing accumulating free radicals [32]. Although mutations in the gene were found,
the evidence was not conclusive, and no causal relationship between these mutations of
SOD1 and keratoconus could be confirmed; further studies were suggested with other
variants of the gene [32].
Inflammation and Immune Response
Although keratoconus is defined throughout the literature and textbooks as a
noninflammatory condition, several studies support the possibility of inflammatory and
immune molecules at work in this condition.
Atopy, a genetically determined state in which the body elicits an exaggerated
response to a foreign stimulus, is known to be associated with increased levels of
immunoglobulin E (IgE) [15,36]. In 1982, Kemp and Lewis reported elevated serum
levels of IgE in 59% of 27 keratoconus patients selected at random [37]. Rahi et al
reported increased serum levels of IgG and IgM in keratoconus patients, while Kemp and
Lewis found no statistically significant difference in these immunoglobulins in
keratoconus patients compared to controls in their study [37,38].
Although an association between eye rubbing in patients with allergic conditions
has been widely reported by several studies, many clinicians and researchers view it as a
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difficult correlation to make due to the nature of self-reported episodes. It is feasible,
however, that these patients rub may their eyes as a result of an already present allergic
reaction taking place.
In 2005, Lema and Durán studied one eye each from 28 patients diagnosed with
keratoconus [36]. They targeted specific cytokines, cell adhesion molecules, and matrix
metalloproteinase 9 (MMP-9). Cytokines, cell adhesion molecules and MMP-9 were
chosen for their association with chronic inflammation [36]. Tear samples of 15 ųLs
were collected from keratoconus subjects who had not worn contact lenses, and had no
active inflammatory systemic or ocular conditions, and then processed with ELISA kits.
Three molecules were found to be at levels significantly higher than normal in
keratoconus patients: IL-6, TNF-α, and MMP-9.
In addition, the levels of each
molecule were strongly correlated with the severity of keratoconus. Following regression
analysis, however, only MMP-9 was found to be an independent variable associated with
the degree of keratoconus. Lema made a compelling remark: “It can be concluded…that
keratoconus cannot be defined any more as a noninflammatory disorder” [36].
In his review article from 2001, Simon Collier addresses MMPs and their possible
role in keratoconus [39]. He specifically addresses the absence of upregulation of MMP9 by Fini, Kenny, and Zhou by suggesting that techniques could be a possible source of
conflict [39-42]. Collier additionally notes that MMP-9 should be induced by IL-1, and
Fabre et al noted that keratoconus fibroblasts release fourfold the number of these same
IL-1 receptors compared to normal corneas [39,43]. It would stand to reason therefore,
that MMP-9 could indeed be overexpressed in keratoconus.
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Furthermore, Li and
AMO Resident Most Challenging Contact Lens Case
Catherine Pannebaker, O.D.
Pflugfelder report that MMP-9 may be “a most amplifying factor for corneal
inflammation” [44].
Other researchers have seen expression of similar molecules in keratoconus
patients. Collier et al were first in demonstrating the expression of membrane-type 1
(MT1) MMP in vivo in keratoconus corneas compared to controls [45]. Ohuchi and
D’Ortho had found previously that MT1-MMP can activate gelatinase A to digest type IV
collagen of the basement membrane; MT1-MMP has the ability to degrade several
extracellular matrix molecules including collagen types I-III [46,47].
It is important to note that the cornea is 70% collagen by weight and is mostly
comprised of Type I collagen [39].
The ectasia and thinning found in keratoconus is
mostly due to a damaged extracellular matrix and a decrease in types I and IV, along with
an increase in type IX collagen – not otherwise found in the basement membrane of the
cornea. [39,48]. Collier et al further hypothesized that MT1-MMP could be released in
response to an inflammatory-related or pathological event, and that it most likely has a
significant role in the etiology if not the progression of keratoconus [45].
Abalain et al studied levels of telopeptides, or collagen degradation products from
26 keratoconus subjects and 36 controls [48]. This study allowed contact lens wear and
an average of 2-7 ųL was collected; active inflammation, ocular surgery and topical
ocular medications were exclusions [48]. The concentration of telopeptides was found by
ELISA kits, and keratoconus patients were found to have 3.5 times the amount of
telopeptides compared to normals; contact lens wear did not significantly modify the
amounts [48]. It was hypothesized that corneal thinning may result from proteolysis of
collagen rather than a decrease in the synthesis of extracellular components [48].
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AMO Resident Most Challenging Contact Lens Case
Catherine Pannebaker, O.D.
Degradative Enzymes/Oxidative Processes
In a hallmark review paper, Christina Kenney and Donald Brown describe a
“cascade hypothesis of keratoconus” in which enzymes in two pathways could lead to
oxidative damage [49]. She notes a decrease in the inhibitors of destructive enzymes are
decreased in keratoconus corneas; they are alpha one (α1) proteinase inhibitor, alpha two
(α2) macroglobulin, and tissue inhibitor metalloproteinase one (TIMP-1); the latter of
which can inhibit cell apoptosis (programmed cell death) and affect cell growth
[15,42,49,51]. Matthews et al noted that relative concentrations between TIMP-1 and
TIMP-3 could be determinants in the balance of cell overgrowth and apoptosis in
keratoconus [52].
Importantly, apoptosis occurs in normal cellular turnover as well as diseases and
wound healing [49]. Edwards et al hypothesized that apoptosis could also occur from the
release of inflammatory cytokines from injured corneal and conjunctival epithelial cells
[26].
Gondhowiardjo et al noted a decrease in aldehyde dehydrogenase Class 3
(ALDH3) and superoxide dismutase, the necessary enzymes to process reactive oxygen
species (ROS), and Kenney surmises that this leads to large amount of cytotoxic by
products in keratoconus corneas eventually leading to corneal thinning and loss of vision
[49,53,54].
Kenney recommends that clinicians educate patients on sources of reactive
oxygen species such as ultraviolet (UV) light, trauma caused by excessive eye rubbing
and poorly fit contact lenses, and uncontrolled allergies. In addition she recommends UV
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AMO Resident Most Challenging Contact Lens Case
Catherine Pannebaker, O.D.
protection in both contact lenses and glasses, and prescribing of topical non-steroidal
anti-inflammatory medications (NSAIDS) and
allergy medications, as well as
preservative-free artificial tears in the management of keratoconus patients [49].
CASE REPORT
Pertinent History and Chief Complaint
Patient AC, a 26-year-old white female, was referred to the clinic by a local
practitioner for contact lens fitting in March, 2007. She had been fitted with soft toric
contact lenses in December of 2006, and was reporting fluctuating and decreased vision
with both her contact lenses and spectacles over the previous two years.
AC’s occupation was programmer, and her systemic history was unremarkable;
she reported taking oral birth control medication. Other pertinent patient and family
history was unremarkable.
The patient’s comprehensive examination in December,
2006, revealed that pupils, motilities, and color vision were within normal limits in both
eyes, although local stereopsis was reduced at 50”. Vision with her current spectacles
was 20/30 OD and 20/40 OS. The manifest refraction determined was -2.75 -4.75 x 057
(20/30) in the right eye, and -3.75 -4.50 x 132 (20/30) in the left eye. The soft toric
contact lens prescription had not been finalized, but trials of Vertex Toric had been
dispensed: Median base curves, 14.4mm diameter and powers of -3.00-2.75 x045 in the
right eye, and -3.50 -3.75 x155 in the left eye.
The previous practitioner had noted no
abnormalies with biomicroscopy, and non-contact tonometry revealed introcular
pressures of 6 mmHg in both eyes at 5pm. Confrontations and amsler grid testing were
reported within normal limits in both eyes. Dilation with 1% Tropicamide revealed that
all aspects of the posterior pole and peripheral fundus examination were within normal
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AMO Resident Most Challenging Contact Lens Case
Catherine Pannebaker, O.D.
limits in each eye. Their impression was myopic astigmatism and slightly reduced
acuities in each eye, and plan was to refer to OSU clinic for further contact lens fitting.
Contact Lens Fitting – First Visit (4/06/07)



Entrance Distance Visual Acuity (Snellen, with CL’s)
OD: 20/25
OS: 20/50 (PH 20/30)
Pupils: 5/5 Round/reactive to light with no afferent pupillary defect OU
Current Soft Contact Lens Assessment
OD
Minimal
Slightly inf
Adequate
9º Nasal
Movement
Centration
Coverage
Rotation

OS
Minimal
Slightly Inf
Adequate
10º Nasal

Manifest Refraction (D)
OD: -2.75 -4.50 x048
20/25
OS: -4.00 -4.50 x132
20/30 PHNI
Simulated Keratometry Readings (Medmont – see pp. 11-12)
OD: 48.8 D @ 134 / 42.7 D @ 044
Trace distortion of mires
OS: 49.4D @ 048 / 42.10D @138
Trace distortion of mires

Biomicroscopy:
OD
Make-up debris
Trace injection
See drawing
Blue/clear
Von Herrick G4
Lids/Lashes
Conjunctiva
Cornea
Iris
Anterior Chamber
OS
Make-up debris
Trace injection
See drawing
Blue/clear
Von Herrick G4
.75mm vascularization OD/OS
Corneas:
1+ SPK
(-) Fleisher’s Ring OD/OS
1+ SPK inf
OD
OS
Stromal thinning seen with
slit lamp beam
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AMO Resident Most Challenging Contact Lens Case
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Catherine Pannebaker, O.D.
AMO Resident Most Challenging Contact Lens Case
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Catherine Pannebaker, O.D.
AMO Resident Most Challenging Contact Lens Case

Catherine Pannebaker, O.D.
Contact Lens Fitting OD (9.5mm diameter PMMA fitting set, with
8.1mm Optic Zone (OZ) and 8.40/10.5 secondary and peripheral
curves) 1 drop Proparacaine instilled OD prior to fitting
1) BC = 7.3/-3.00 (Approximately Average of K readings)
Fit
Central Flourescein Pattern
Edge Lift
Other
Lid Attached (LA)
Central Pooling
Minimal 360º
Mid peripheral bearing
2) BC = 7.5/-3.00 (Slightly flatter since central pooling)
Fit
Central Flourescein Pattern
Edge Lift
Other
LA
Feather touch
Minimal 360º
Slight Mid peripheral bearing
Spherical over-refraction (SOR) -5.00D (vertexed power -4.75, 20/20)

Contact Lens Fitting OS (9.5mm diameter PMMA fitting set, with
8.1mm OZ and 8.40/10.5 secondary and peripheral curves)
1 drop Proparacaine instilled OD prior to fitting
1) BC = 7.2/ -3.00 (Approximately Average of K readings)
Fit
Central Flourescein Pattern
Edge Lift
Other
LA
Central pooling
Minimal 360º
Central Bubble
2) BC = 7.5/-3.00 (Since central pooling/bubble)
Fit
Central Flourescein Pattern
Edge Lift
Other
LA
Slight pooling
Minimal 360º
Small Central bubble
3) BC = 7.6/-3.00 (Since still central pooling/bubble)
Fit
Central Flourescein Pattern
Edge Lift
Other
Interpalpebral – inf centration
Trace pooling @ feather touch
Minimal 360º
No bubbles
SOR -5.75D (vertexed power -5.37, 20/20)
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AMO Resident Most Challenging Contact Lens Case
Catherine Pannebaker, O.D.
 Final Contact Lens Order – based on spherical over-refractions and
flourescein patterns and trial lens parameters
Base
Curve
(BC)
OD
OS
7.5
7.5
Optic
Zone
Diameter
(OZD)
7.7
7.6
Secondary Curve
Radius/width
in mm
(SC/width)
8.4 / .7
8.4 / .75
Peripheral Curve
Radius/width in
mm
(PC/width)
10.5 /.2
10.5 /.2
Overall
Power
Diameter
(OAD)
9.5
9.5
-7.75
-8.37
Materials: Fluoroperm (FP) 60; Blue Tint (dot OD)
Assessment
Plan
1) Mild Keratoconus OD/OS
1) Ordered gas permeable lenses above.
Flatten peripheral curves to increase
- improvement in vision OD/OS with
edge clearance in both eyes.
gas permeable contact lenses today
FP 60 material ordered
- Medmont Topography performed
for increased oxygen permeability given
power. Application/removal instruction
- Discussed benefits of GP vs soft toric
at dispense. Gave patient sample of
lenses.
artificial tears (ATS) twice or more daily
each eye. Educated pt about nature of
condition and possibility of several visits
ahead.
First Dispense Visit (4/20/07)
 Pertinent new history: Patient using artificial tears 2-4 times daily;
No changes in systemic health since last visit.
 Entrance Distance Visual Acuity (Snellen, with SCL’s)
OD: 20/25
OS: 20/50 (PH 20/30)
 Dispensed new contact lenses in previously ordered parameters and
allowed to settle 20 minutes
 Visual Acuity with new contact lenses
OD: 20/20
OS: 20/20
 Contact Lens Evaluation
OD
OS
LA(falls after few seconds)
LA (falls after few seconds)
Fit
Central Flourescein Feather touch w/ slight pool Feather touch w/ slight pool inf/sup
inf/sup
Pattern
Adequate except minimal @ 3/9 Adequate except minimal @ 3/9
Edge Lift
 No over-refraction performed this visit since 20/20 vision
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AMO Resident Most Challenging Contact Lens Case
Catherine Pannebaker, O.D.
 Patient completed application and removal process along with
cleaning regimen
 Diagnostic Assessment and Plan
Adequate fit today OD/OS with rigid contact lenses. Application and removal
process successful. Gave patient Boston Simplus Solution. Pt to wear CL’s 3
hours today plus 1 hour daily until 1 week check. Continue artificial tears 2-4
times daily OD/OS. Pt understands to call clinic immediately if pain redness
or decrease in vision occurs.
One week check (04/27/07)
 Pertinent new history: Unremarkable
 Entrance Distance Visual Acuity (with new GP lenses)
OD: 20/20
OS: 20/20
 Over-refraction
OD: Plano
OS: Plano
 Contact Lens and surface evaluation
OD
Poor LA/falls immediately
Fit
Central Flourescein Pattern Feather touch w/ slight
pool inf/sup
Poor 360º
Edge Lift
Good
wettability;
no
Other
deposits

Biomicroscopy without CL’s:
OD
Makeup debris
Trace injection
G1 3/9 stain
Lids/Lashes
Conjunctiva
Cornea/staining


OS
Poor LA/falls immediately
Feather touch w/ slight pool
inf/sup
Poor 360º
Good wettability; no deposits
OS
Makeup debris
Trace injection
G1 3/9 stain
Continue with CL fitting since poor fit OD/OS
Contact Lens Fitting OD (10.8mm diameter Dyna Z Intral Limbal,
with 9.0mm OZD)
1) BC = 7.85/-1.37 (Approximately flat K readings)
Fit
Central Flourescein Pattern
Edge Lift
Other

Lid Attached (LA)
Central Pooling
Adequate except lift off inferior
Good centration and movement
SOR OD -4.00 (vertexed power -3.87)
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AMO Resident Most Challenging Contact Lens Case
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Catherine Pannebaker, O.D.
Contact Lens Fitting OS (10.8mm diameter Dyna Z Intral Limbal,
with 9.0mm OZD)
1) BC = 7.85/ -1.37 (Approximately Average of K readings)
Fit
Central Flourescein Pattern
Edge Lift
Other
LA
Slight central touch
Lift off inferior
Nasal centration
2) BC = 7.67/-1.75 (Since central touch and inferior lift off)
LA
Fit
Feather touch
Central Flourescein Pattern
Good except inf lift off
Edge Lift
Better centration
Other


SOR -4.25 (Vertexed power -4.00, 20/20)
Final Contact Lens Order – based on spherical over-refractions and
flourescein patterns and trial lens parameters
BC
OZD
OD
7.85
9.0
OS
7.67
9.0
Peripheral
Curve OAD
Parameters
1 step flat with 3 steps 10.8
flat @ 270º 1.0 Prism
1 step flat with 3 steps 10.8
flat @ 270º 1.0 Prism
Power
-5.25
-5.75
 Material – Menicon Z
 Diagnostic Assessment and Plan
Inadequate fit with previously dispensed GP CL’s. Refit today with Dyna Z
IL CL’s in above parameters. Pt to return to SCL wear until new CL’s arrive.
Continue ATs at least two times daily.
Dispense Visit (5/11/07)
 Pertinent new history: Patient using artificial tears 2-4 times daily;
No changes in systemic health since last visit.
 Entrance Distance Visual Acuity (with SCL’s)
OD: 20/25
OS: 20/50 (PH 20/30)
 Dispensed new contact lenses in previously ordered parameters and
allowed to settle 20 minutes
 Visual Acuity with new contact lenses
OD: 20/20
OS: 20/20
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AMO Resident Most Challenging Contact Lens Case
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Catherine Pannebaker, O.D.
Contact Lens Evaluation
OD
LA (falls after few seconds)
Fit
Central Flourescein Feather touch w/ slight pool
inf/sup
Pattern
Slightly excessive inferiorly
Edge Lift
OS
LA (falls after few seconds)
Feather touch w/ slight pool inf/sup
Slightly excessive inferiorly
 No over-refraction performed this visit since 20/20 vision
 Diagnostic Assessment and Plan
Adequate fit with Dyna Z IL CL’s for Keratoconus OD/OS. Instructed pt to
build up wearing time again, and to only use Boston Simplus solution for
cleaning. RTC one week for check.
One week check (05/18/07)
 Pertinent new history: Pt reports slight dryness with CL’s after 8 hours;
using ATs 4x daily.
 Entrance Distance Visual Acuity (with new GP lenses)
OD: 20/20
OS: 20/20
 Over-refraction
OD: Plano
OS: Plano
 Contact Lens and surface evaluation
OD
Poor LA/falls immediately
Fit
Central Flourescein Pattern Feather touch w/ slight
pool inf/sup
Adequate; increased inf
Edge Lift
Poor wettability; a few
Other
deposits present

OS
Poor LA/falls immediately
Feather touch w/ slight pool
inf/sup
Adequate; increased inf
Poor wettability; a few
deposits present
Biomicroscopy without CL’s:
Lids/Lashes
Conjunctiva
Cornea/staining
OD
Makeup debris
G1 nasal injection
G1 3/9 stain
OS
Makeup debris
G1 nasal injection
G1 3/9 stain
 Cleaned lenses with Boston Lab cleaner in office today to remove
deposits
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Catherine Pannebaker, O.D.
 Diagnostic Assessment and Plan
Adequate fit with Dyna Z IL CL’s for Keratoconus OD/OS, yet dryness
symptoms with decreased wettability and surfacde deposits present this visit.
Some staining and injections present this visit. Cleaned lenses in office today.
Pt to limit wear time to 8 hours until next visit and continue ATs 2-4x daily.
Consider refit next visit if necessary. Instructed pt to build up wearing time
again, and to only use Boston Simplus solution for cleaning. RTC one week
for check.
Contact Lens check (05/30/07)
 Pertinent new history: Eyes feel dry after one hour. Yesterday night OS
CL dislodged causing slight redness, tearing and pain. Using ATs liberally
since last night
 Entrance Distance Visual Acuity (with new GP lenses)
OD: 20/20
OS: 20/20
 Over-refraction
OD: Plano
OS: Plano
 Contact Lens and surface evaluation
OD
Poor LA/falls immediately
Fit
Central Flourescein Pattern Feather touch w/ slight
pool inf/sup
Adequate except slightly
Edge Lift
increased inf
Poor wettability; a few
Other
deposits present
 Biomicroscopy without CL’s:
Poor wettability;
deposits present
a
few
OS
Makeup debris
G1 nasal injection
Paracentral corneal abrasion 2.5mm in length
which picks up stain
Diagnostic Assessment and Plan
Paracentral corneal abrasion OS d/t dislodged CL. Pt to discontinue CL
wear and wear spectacles. Prescribed Vigamox ophthalmic solution 1gt
q1hr OS while awake. Pt to return tomorrow for cornea check. Advised
decrease in makeup to avoid infection. Gave cell number and told pt to
call if any changes such as discharge develop.
Lids/Lashes
Conjunctiva
Cornea/staining

OS
Poor LA/falls immediately
Feather touch w/ slight pool
inf/sup
Adequate
OD
Makeup debris
Slight injection
G1 3/9 stain
OS Cornea check (05/31/07)
 Pertinent new history: Pt using Vigamox 1gt q1hr OS, and reports no
discharge, redness or pain this visit.
19
AMO Resident Most Challenging Contact Lens Case


Entrance Distance Visual Acuity (with spectacles)
OD: 20/30
OS: 20/40
Biomicroscopy:
Lids/Lashes
Conjunctiva
Cornea/staining

Catherine Pannebaker, O.D.
OD
Trace Makeup debris
trace injection
Trace SPK 3/9
OS
Trace Makeup debris
trace injection
G1 Stain over 1mm abrasion
Diagnostic Assessment and Plan
Paracentral corneal abrasion OS d/t dislodged CL much improved. Pt to
continue CL wear Vigamox qid OS and one week for cornea check and
possible refit of CL’s. Pt to wear spectacles until that time. Re-educated
pt about nature of condition and will try yet a different type of lens on next
visit to get a good fit. Pt enjoys the vision of GP lenses and willing to be
refit for corneal health.
OS Cornea check and possible CL fit (06/08/07)
 Pertinent new history: Pt using Vigamox 1gt qid OS, and reports no
discharge, redness or pain this visit.
 Entrance Distance Visual Acuity (with spectacles)
OD: 20/30
OS: 20/40
 Biomicroscopy:
Lids/Lashes
Conjunctiva
Cornea/staining

OD
Trace Makeup debris
trace injection
clear
OS
Trace Makeup debris
trace injection
Clear – no abrasion present
Contact Lens Fitting OD (11.2mm diameter Rose K IC)
1) BC = 7.85/-5.00 (same as previously fit GPs)
Definite Central Touch
Central Flourescein Pattern
2) BC = 7.67/-5.00 (since central touch)
Central Flourescein Pattern
Central Touch
3) BC 7.34/-5.00 (since central touch)
20
AMO Resident Most Challenging Contact Lens Case

Contact Lens Evaluation
Fit
Central Flourescein Pattern
Edge Lift


Catherine Pannebaker, O.D.
OD
LA
Alignment pattern
Minimal at 3/9
SOR OD -3.00 (20/20)
Contact Lens Fitting OS (11.2mm diameter Rose K IC)
1) BC = 7.67/-5.00 (same as previously fit GPs)
Some Central Touch
Central Flourescein Pattern
2) BC = 7.50/-4.00 (since central touch)
 Contact Lens Evaluation
Fit
Central Flourescein Pattern
Edge Lift
Other


BC
OD
OS

OD
LA
Alignment pattern
Minimal at 3/9
Few midperipheral bubbles
SOR OD -3.50 (20/20)
Contact Lens Order – based on spherical over-refractions and
flourescein patterns and trial lens parameters; consulted with lab
about minimal edge lift at 3/9 OD/OS. Toric peripheral curves
recommended.
OZD
7.34
Proprietary
7.50
Proprietary
 Material Boston EO
Peripheral
Parameters
Step 1 Toricity
Step 1 Toricity
Curve
OAD
Power
11.2
11.2
-8.00
-7.50
Diagnostic Assessment and Plan
Paracentral corneal abrasion OS resolved. Pt refit this
visit into Rose K IC reverse geometry design OD/OS. Pt
to discontinue Vigamox OS and use ATs 2-4x daily and
wear spectacles until dispense visit.
Dispense Visit (6/22/07)
 Pertinent new history: Patient using artificial tears 2-4 times daily;
No changes in systemic health since last visit.
21
AMO Resident Most Challenging Contact Lens Case


Catherine Pannebaker, O.D.
Entrance Distance Visual Acuity (with spectacles)
OD: 20/30
OS: 20/40
Biomicroscopy:
OD
OS
Trace Makeup debris
Trace Makeup debris
Lids/Lashes
trace injection
trace injection
Conjunctiva
clear
Clear – no abrasion present
Cornea/staining
 Dispensed new contact lenses in previously ordered parameters and
allowed to settle 20 minutes
 Visual Acuity with new contact lenses
OD: 20/20
OS: 20/20
 Contact Lens Evaluation
OD
OS
Central alignment
Central Flourescein Central alignment
Pattern
Minimal 360º
Minimal 360º
Edge Lift
Minimal movement
Minimal movement
Other
 The contact lenses were modifed in office at this point to attempt to
dispense at this visit. A 12.50mm tape tool was used to modify the
peripheral curves of each contact lens with the goal of increasing edge
lift and movement for adequate tear exchange. This modification
process was performed in small increments a total of three times. The
lenses were cleaned with Boston lab cleaner following modification.
 Visual Acuity with modified lenses
OD: 20/20
OS: 20/20
 Contact Lens Evaluation after modification
OD
OS
Central alignment
Central Flourescein Central alignment
Pattern
Good 360º
Good 360º
Edge Lift
Good movement
Good movement
Other

Diagnostic Assessment and Plan
Adequate fit achieved today with Rose K IC CL’s OD/OS following inoffice modification. Pt to slowly increase wearing time and RTC within
two weeks for progress check.
Contact Lens check (07/02/07)
 Pertinent new history: Pt reports good vision and comfort with modified
Rose K IC CL’s OD/OS. Pt using ATs prn.
22
AMO Resident Most Challenging Contact Lens Case



Entrance Distance Visual Acuity (with new GP lenses)
OD: 20/20
OS: 20/20
Over-refraction
OD: Plano
OS: Plano
Contact Lens and surface evaluation
OD
Central Flourescein Central alignment
Pattern
Good 360º
Edge Lift
Good movement; no deposits
Other

Catherine Pannebaker, O.D.
OS
Central alignment
Good 360º
Good movement; no deposits
Biomicroscopy without CL’s:
OD
OS
Trace makeup debris
Trace makeup debris
Lids/Lashes
Trace injection
Trace injection
Conjunctiva
Trace 3/9 stain
Trace 3/9 stain
Cornea/staining
 Diagnostic Assessment and Plan
Good fit, vision and comfort with modified Rose K IC GPs for
keratoconus OD/OS. Pt to return in one month for progress check. RTC
sooner if problems arise.
Contact Lens check (08/03/07)
 Pertinent new history: Unremarkable
 Entrance Distance Visual Acuity (with GP lenses)
OD: 20/20
OS: 20/20
 Over-refraction
OD: Plano
OS: Plano
 Contact Lens and surface evaluation
OD
Central Flourescein Central alignment
Pattern
Good 360º
Edge Lift
Good movement; trace deposits
Other
OS
Central alignment
Good 360º
Good movement; trace deposits
 Contact lenses cleaned with Boston lab cleaner in office today. Pt
educated on Lobob Optimum system for cleaning contact lenses more
thoroughly.
23
AMO Resident Most Challenging Contact Lens Case

Catherine Pannebaker, O.D.
Biomicroscopy without CL’s:
OD
OS
Trace makeup debris
Trace makeup debris
Lids/Lashes
Trace injection
Trace injection
Conjunctiva
Trace 3/9 stain
Trace 3/9 stain
Cornea/staining
 Diagnostic Assessment and Plan
Good fit, vision and comfort with modified Rose K IC GPs for
keratoconus OD/OS. Trace deposits on lenses today. Contact lenses
cleaned and pt educated about Lobob Optimum cleaning system for
thorough cleaning of lenses. Pt to return to clinic if necessary if problems
arise before comprehensive examination in March. Pt pleased.
DISCUSSION
Keratoconus can be managed using many contact lens types to provide good
vision and comfort for the patient. Smaller and steeper designs of gas permeable lenses
are usually used for smaller, more centrally located “cones” or focalized areas of corneal
ectasia. As the area of the cone increases and/or appears more inferior, larger diameter
lenses with larger optic zones tend to be used.
In the case of AC, initial topography
readings showed a medium-sized area of slightly inferior ectasia, therefore, large
diameter lenses were fitted.
The smaller topography platforms are recommended for their increased number of
areas of calculation for irregular corneas, and therefore the Medmont platform was
utilized for an increase in accuracy of the simulated keratometry readings [55]. Another
interesting point about topography is that, although keratoconus corneas usually present
with irregular astigmatism, the mathematical algorithm built into most platforms is
designed to give simulated keratometry readings showing regular astigmatism [55]. This
is a very minor issue given the fact that topography has revolutionized the ability to
diagnose keratoconus and other corneal abnormalities over the past few decades. Patient
24
AMO Resident Most Challenging Contact Lens Case
Catherine Pannebaker, O.D.
AC’s maps revealed the possibility of an emerging “kissing bird” appearance often
associated with Pellucid Marginal Degeneration (PMD); this was yet another reason to
concentrate on larger lenses at the fittings, as most clinicians agree that a larger diameter
lens has improved success with PMD patients.
It is not uncommon to see a specialty contact lens patient for several visits. Each
time this patient was refit, the choice was made to go to different diameters and types of
lenses, yet still fit with a larger diameter considering topography.
It is important to learn the different aspects of specialty lenses, especially those
with any proprietary parameters, such as flattening peripheral curve systems, optic zone
parameters, availability of quadrant-specific alterations, and toricity options.
These
added features can help the clinician to further customize lenses to achieve the best fit
possible. It is also important to move on to a different lens when the current one is not
working for the patient, and change materials when sudden depositing issues arise.
The incident with the disloged left contact lens was particularly disturbing to both
the patient and the practitioner in that the corneal health was compromised for a time and
the fitting process further delayed. Although the abrasion was surprisingly large, the
patient reported only slight irritation or pain most likely due to decreased corneal
sensitivity that often occurs in conditions such as keratoconus. The patient’s compliance
with instilling drops and abstaining from contact lens wear were key in the healing
process. The patient was motivated by the clear vision with gas permeable lenses that she
had not experienced previously with soft toric contact lenses. Also important was that
the patient was extensively educated at more than one visit regarding the nature of her
25
AMO Resident Most Challenging Contact Lens Case
Catherine Pannebaker, O.D.
ocular condition, and the possibility for multiple visits since had not been previously fit
into gas permeable contact lenses prior to visiting the clinic.
An additional skill that can be important on occasion is the ability to modify
contact lenses in the office. This procedure of course requires not only the proper
equipment, but adequate training so that the contact lenses are not damaged in the
modification process. When performed properly, in-office modification can enable the
patient to leave with contact lenses rather than having to place yet another order with a
lab. It is important to properly clean lenses following modification to ensure proper
wettability.
Finally, it is important to educate patients on cleaning systems options. If onestep solution systems prove inadequate, a multi-step system may be necessary to ensure
proper cleaning and good comfort of the lenses.
In conclusion, it can be very challenging, yet very rewarding to properly fit
keratoconus patients with gas permeable contact lenses. In addition to proper training on
fitting and lens options, it is important to educate the patient about their condition and the
possibility of multiple visits – especially with patients who are fit for the first time.
Patients can experience an improvement in vision and therefore lifestyle when fit
properly with gas permeable contact lenses.
26
AMO Resident Most Challenging Contact Lens Case
Catherine Pannebaker, O.D.
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29