Download Special Cases For CL

Special Cases for CL
Toric SCL
SCL Toric Evaluation
 When we select a patient for soft toric lens fitting it is usually because they have
low to moderate amounts of refractive cylinder in their prescription. When we
examine the amounts of cylinder available in standard toric lenses, it usually falls
between -0.75 and -1.75 diopters. Custom soft toric contact lenses are available in
a wider variety of both sphere and cylinder powers, but are fit with much less
frequency due to increased costs and decreased successes.
 When evaluating whether a patient may be an appropriate candidate for a soft
toric contact lens fitting, the patient’s refractive error must be assessed.
Remember that in standard parameters the only cylinder powers that are available
to us classically fall between -0.75 and -1.75 diopters cylinder. Additionally, most
standard soft toric contact lenses are only available in sphere powers between
+4.00 and -6.00 diopters. The OAD of the lens must also be taken into
consideration. Soft toric contact lenses have a tendency to be larger than most soft
sphere contact lenses. This increased size helps aid in stabilizing the rotation of
the contact lens. However, in individuals with small palpebral fissures, this
increased OAD may become an issue. Soft toric contact lenses usually come in
diameters between 14.0-15.0mm.
 Some of the other special features that we have become accustomed to with soft
spherical contact lenses are available to us with soft toric lenses as well, but on a
limited basis. For example, soft toric lenses are available in cosmetic tints and
opaque tints. Additionally, some soft torics lenses are approved for EW or FW
modalities. It should be realized that with every special feature, the total amount
of lenses available is diminished significantly.
Selection of a Diagnostic Soft Toric Contact Lens
 With the combinations between each patient on palpebral fissure diameter, BC,
sphere, cylinder, and axis, no office can possess trial contact lenses that will
perfectly match each patient. Therefore, the following items will help you make
some educated choices about what trial lens to select.
 If you have a choice between two OADs when selecting a diagnostic CL, select
the smaller of the two lenses as your first choice.
 When selecting BC for the initial diagnostic CL select the flatter BC if you have
only 2 choices, or select the middle BC if you have 3 choices.
 When selecting the power of the soft toric CL, pick both the sphere and axis as
close to the patient’s refraction as possible as these two parameters are the most
important.
 The value of the cylinder power is the least important value in trial lens selection.
As long as all the other parameters are considered first, then select the cylinder
power as close to the patient’s refraction as possible.
Soft Toric Contact Lens Fit Assessment
 Although many of the rules applied to soft toric contact lens fitting are the same
as soft sphere contact lenses, some additional items are also evaluated.
 Because all types of soft toric contact lenses use some method od stabilization, the
diagnostic contact lens should be allowed to equilibrate for somewhere between
10-30 minutes before a thorough evaluation of the lens performed. However, an
initial gross observation of the diagnostic lens should be made shortly after
application to determine if the coverage, centration, etc is at least in the ballpark.
If the diagnostic lens is grossly inappropriate, then further evaluation is a waste of
time.
 After the lens has equilibrated, an overrefratction should be performed. A spherocylinder overrefraction to BVA should be obtained as well as a spherical only
overrefraction to BVA.
 After the OR is performed, a thorough fit assessment is completed. As with soft
spherical contact lenses, those characteristics of the fit that are evaluated are
centration, coverage, MOB, lag, and sag. The criteria for an acceptable fit are the
same as that applied to a soft sphere.
 There are two additional aspects of lens that are evaluated on a soft toric contact
lens, these are the characterictics of rotation and stability. Each soft toric lens has
markings on it in some location that aids in determining the amount that the lens
has rotated or positioned on the eye.
o The first step is to locate these markings with the slit lamp. Then an
estimation of the amount of rotation is attempted and recorded. If the eye
is divided into clockdial increments, rotation of the lens one clock hour
represents 30 degrees. With certain slit lamps, the beam of the slit lamp
can be aligned with the orientation marks of the toric lens, and the amount
of rotation can be directly measured using the protractor device.
Recording of the direction of the rotation, either temporal or nasal, along
with a drawing is also required. Rotation over 20 degrees is usually
considered unacceptable and another diagnostic lens choice should be
made.
o Stability of the rotation of the contact lens on the eye is also evaluated. It
is logical that for a patient to obtain good VA out of a soft toric lens, the
lens must maintain the orientation of its cylinder correction at a constant
position on the eye. This is why the stability of the lens is important. Ask
the patient to give you a full, strong blink while you observe the behavior
of the lens behind the slit lamp. The rotation of the contact lens should
stay relatively constant even during the blink for acceptable visual
performance. Excessive rotation of the contact lens on blink indicates the
need for another diagnostic lens.

Rotational Stabilizers
o Prism “ballast” (watermelon seed effect)
 3/4D  2D
 Not custom ordered
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Increased prism
 Increased stabilization for decreased rotation
 Increased thickness, therefore decreased O2.
o Decreased O2 means increased neovascularization.
 Comfort?
 Adds a BD affect
o Eccentric lenticulation
 Increased OAD (~15mm)
o Back surface toric
 Stabilization? – all have prism (back and front)
 Back surface vs. front surface toric
 Lathe-cut usually back surface toric
 Molded usually front surface toric
 When do you prescribe front vs. back surface SCLs?
o On the eye, probably not a significant factor.
Choose based on other factors.
o Double slab-off
 2 thin areas
 Least effective stabilizer?
 Lids grab onto the thin areas?
 Most comfortable
 Made quickly because molded.
o Truncation (dinosaur)
 Problem with stabilization and comfort.
o Combination
o Large OAD
 Contributes to lens stabilization
 Allows for more pronounced thick and thin areas
Lens Markings
o Base Down Positions
 Usually at 6 o’clock
 Scribe mark, three scribes marks, dots
 Separation of scribe marks
o 3 and 9 o’clock markings
o How do you quantify rotation?
 Clock
 Each hour is 30 degrees
 Spectacle trial frame
 Slit lamp housing angle
 Slit lamp eyepiece reticule
 Markings cover so many degrees due to magnification.
 Over-refraction
 Use the cross-cyl formula. This is the most accurate.
o LARS
 Left add, right subtract
 Add/subtract to the axis of the subjective rx, not the DxCL.

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If the diagnostic lens is rotated, then the dispensed lens should be
rotated.
 Ex 1
 Refraction:
-2.00 -1.50 x090
 Diagnostic CL:
-1.50 -1.50 x100
 Rotation:
10 degrees to the R and stable
 Order:
-2.00 -1.50 x080
o On D-day, the dot should be 10 degrees to the R
 Ex 2
 Refraction:
+2.00 -2.00 x180
 Diagnostic CL:
+2.50 -1.75 x170
 Rotation:
10 degrees to the L and stable
 Order:
+2.00 -2.00 x010
o Dot should still be 10 degrees to the L
Patient Selection Guidelines
o Refractive error
 Sphere
 +4.00 tp -6.00D
 Cylinder
 >0.75 to <3.00D
 corneal vs. internal cyl
 Axis
 Any, but obliques tend to have worse rotation.
o Realistic Expectations
 Visual compromise vs. RGP or spectacles or refractive surgery.
Selection of Brand
o DW vs EW vs Tint vs Replacement Schedule
 Don’t do EW
 Only order this to make the profile thinner, but don’t use as
EW
 It increases the oxygen, but not as stable.
o Availability of Parameters
 Inventory vs. custom
 Custom: increased cost and delivery time.
o Availability of Warranty/Guarenteed Fit Program
 Which company gives you least hassle?
o Refractive Error
 High sphere and low cylinder
 Cyl doesn’t have to be as accurate
 Go with a thinner lens (O2 permeability more important
than stability)
 Low sphere and high cyl
 Cyl needs to be accurate
 Use CL with increased prism
 Orientation of cyl axis
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Double slab off- ATR/WTR
Prism- Oblique
Fitting
o Empirical vs. Trial Lens Fitting
 Fitting without patient in the office. This is done with faraway
patients.
 Trial lens Fitting
 Selection of Diagnostic CL
o Availability of parameters
o Selection of BC/OAD
 BC- avg K
 OAD- use larger, because it increases the
rotational stability.
o SPHERE, cylinder, AXIS
 Choose sphere and axis first. These play
more roles in the rotation.
 With a -2.00 -2.00 x090, choose -2.00 -1.00
x090
 Apply lens and allow to equilibrate
o 10-30 min
o apply BD
o teach technique to the patient.
 Evaluate the fit
o Coverage/centration/movement
 Evaluate rotation/stability (consistency of rotation)
o LARS
o “Dial lens”  Becherer Twist
 with displacement, should return within 10
blinks.
 Perform OR (sphero-cyl)
o Hints
 Add + to sphere for lenses with thick profiles. This is due to
flexure effects, not TL. Prescribe less cyl than SRx. This does not
occur with double slab-off.
Ordering a Soft Toric Contact Lens
 The first step in selecting a soft toric contact lens is to remind yourself of exactly
what parameters the lens you want has available. Every parameter and power is
not available in soft toric lens design. You will need to refer to Tyler’s Quarterly.
 Final sphere power can be determined in one of two ways (both of these should
correlate). The sphere power can be determined by taking the vertexed sphere
power of the refraction or by combining the power of the diagnostic trial lens and
the spherical over-refraction (if possible). These two values should be in
agreement.
 To determine the axis of the ordered lens based on the rotation noted on slit lamp
observation, if all other characteristics of the diagnostic lens were acceptable, then
compensation for the observed rotation is made. The rule that is applied is called ,
LARS, which stands for left add, right subtract. This indicates that if the lens
rotates to the clinician’s left, the amount of rotation is added to the patient’s
refractive axis and if the rotation is to the clinician’s right, the value would be
subtracted from the patient’s refractive axis, not tha axis of the diagnostic contact
lens.
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CL Correction for Presbyopia
Advantages
o Dependent on SRx
o Motivated- more proactive with healthcare
o Follow instructions?
o Possess discretionary funds
o Decreased corneal and lid sensitivity due to lax lids, therefore increased
tolerance.
o May have long history of CL wear.
o With large prescriptions, there is a better image size and increased
periphery. This also means that it could be covered by insurance.
Disadvantages
o Decreased tear volume/quality due to hormonal changes, etc.
o More medications that might dry eye
o Fear of CL (or anything touching the eye if never worn before)
o Decreased importance of cosmesis
o Medication interactions
o Decreased pupil size.
Therefore, establish realistic expectations
Options
o Distance CL with near overcorrection (like OTC readers)
 Most common
o Near CL with distance overcorrection (Good for those with a lot of
nearwork)
o Monovision
o Bifocal CL
 Alternating
 Analogous to SRx bifocals: 2 segs with 2 powers
 Lens has a small seg (3mm) and needs to translate
 With large pupils you can have simultaneous vision
 Simultaneous
 See distance and near at the same time (analogous to
progressives)
 Can also get intermediate
 Produces ghost images and brain chooses which to see.
 This decreases distance VA a little.
o Modified/Enhanced Monovision
 Modified- 1SV and 1 bifocal CL

 Enhanced- Can overlap Rxs (Dist/Int and Int/Near)
o All options are available with either rigid or SCL
 Except no translating deisgn in SCL because it is too large to
translate.
Examples
o 1: Distance CL with reading overcorrection
 Patient 47 requires a +1.50 add

43.75 DS
Km
43.75DS
-4.25 -0.50 x170
SRv
-4.50 DS
43.00/-3.75/SCCO
CLRx
43.00/-3.75/SCCO
+0.25 -0.50 x170
OR
plano DS
AA/DS/Avg/C
FP
AA/DS/Avg/C
 Prescribe spectacle overcorrection of
o OD: +1.75 -0.50 x170
 OR + Add
 +1.50 DS wouldn’t be bad, but with ATR,
Rx the cyl for sure.
o OS: +1.50 DS
o Use near work when wearing CLs
o Specify on CLRx for near use over the CL.
o Need to specify near PD
o 2: Near CLs with distance overcorrection
 Patient 42- requires a +1.00 Add

43.50 DS
Km
43.75/43.25 x180
+2.00 DS
SRv
+1.50DS
42.75/+2.75/SCCO
Dist CLRx 42.75/+2.25/SCCO
plano DS
Dist OR
+0.25 -0.50 x090
42.75/+3.75/SCCO
Near CLRx 42.75/+3.25/SCCO
-1.00DS
Near OR
-0.75 -0.50 x090
AA/DS/Avg/C
FP
AA/-0.50 x180/Avg/C
 Near OR done at distance. There is no such thing as a near
Rx.
 Prescribe spectacle correction of
o OD: -1.00DS
o OS: -0.75 -0.50 x090
o To be worn over CLs for driving, distance tasks.
o Prescribing the cyl justifies the glasses even more.
o This is often done with keratoconics.
Monovision
 One eye fit for distance/ one eye fit for near
 Simultaneous distance and near
 #1 presbyopic CL option
o only option for those with LASIK
o success rate? 80-90% (most successful fitting modality)
o Adaptation period? 15 min-1 week depending on the patient
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 Usually occurs within 3 days.
Advantages
o Can use same fitting philosophies and lens materials (simple)
o Can use same lens replacement schedule (all lens types)
o Less expensive- same as SV
o Good distance, good near
Disadvantages
o Adaptation problems
 Near eye is constantly defocused, some patients get over it, some
don’t. Give them about 2-3 weeks. If they don’t get it, they wont
ever.
o Interferes with stereopsis and binocular vision
o Glare at night.
 Some patients will buy a pair of glasses to wear over monovision
when driving at night. Offer it if they complain about this.
 Due to near defocus.
 Most adapt to this.
Don’t fit
o Patients who do mostly near or mostly distance work
o Patients with reduced VA in one eye (amblyopes)
Selection of near eye
o Dominant eye for distance (most prevalent philosophy) if mostly distance
o Visa versa (dominant eye for near if do mostly near work)
o Near lens for placement of vocational (typing) or avocational (car mirror)
needs. ;
o If one eye has good unaided distance vision- fit other eye for near.
o If one eye has good unaided near vision- fit other eye for distance
o With RGPs, fit both eyes because they need the same sensation.
Near Stereoacuity
o Stereo is only needed with very detailed near work, therefore don’t use
monovision
o Koetting (1970) found 94% of monovision patients had normal stereopsis
when age matched.
o Christie and Sarver (1971) found little or no loss of stereopsis with adds of
<1.00 D
o Blake, et al. (1980) reported that a “suppressed” eye may contribute to
stereopsis
o McGill and Erickson (1988) reported reduction in stereoacuity with
monovision. They found that it was a function of the add. Increased add
means decreased stereo.
Distance Stereoacuity
o This is not as important
o Back (1987) found that monovision wearers exhibited a significant loss in
distance stereoacuity when compared to soft bifocal CL wearers.
o Rouse et al. (1988) found that static stereo deficient subjects can use
dynamically changing disparities to make depth judgements.
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Binocularity
o Loshin, Loshin, and Comer (1982) found that for adds up to +1.50,
binocular summation in contrast sensitivity function was lost for middle
frequency and high frequency (high detail). It was retained for low
frequency. But, all binocular summation was lost with adds greater than
+2.00D.
Peripheral Vision
o McLendon et al (1968) tested visual field using a 3mm target. They found
that there was a decrease in the VF of 0.2 degrees for the eye corrected for
near as compared to the field of the eye corrected for distance. But, there
was an overall increase of about 5 degrees for CL correction as compared
to spectacle correction.
o Lit, Stern, and Edrington (1991) found that adds <2.00D had little or no
effect on the binocular field of view. Subjects demonstrated a 2-5 degree
field compression with adds >2.00D
 Note: motion detection in the peripheral retina is least affected by
blur.
Legal concerns of monovision
o Harris and Classes (JAOA, 1988)
 Alternatives need to be explained.
 Limitations should be presented
 Have patient sign informed consent
 Caution against driving or operating heavy machinery during
adaptation to monovision
 Need to instruct patient of adaptation.
o Nakagawa (Optom 2000)
 National Transportation Safety Board (NTSB) determined
probable cause of Delta aircrash on 10/19/1996 due to inability of
pilot to overcome misconception of airplane’s position relative to
the runway due to monovision.
o Slutsky, Wang, Edrington (OVS 2000)
 Pilot’s landing ability not related to distance stereo.
Multifocal Rigid CLs
 Case History
o CL History
 Previous wearer? Likes? Dislikes? Success? RGPs? Monovision?
o Medical History
 Medications that can affect CL wear?
o Occupational and Avocational Needs
 Computer use? If it is more than 30% of their time, you may want
to consider aspheric lenses, which may increase the intermediate
vision.
o Motivation and dedication
 Return for F/U? very important! It can take up to 6 weeks to fit
some lenses. Ask for their commitement.
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o Awareness of cost
 About $300. Doubles for SCL. Premium lenses require a premium
price. Patient education must reinforce this.
CL Fitting
o Refraction
 Push the most plus distance vision. This makes the add work
better. Over-minusing a patient at distance causes decreased near
Vas.
o Position of eyelid
 We don’t want any bug eyes or squinty eyes.
o Corneal Curvature with keratometry
 Topography is an overkill.
o Pupil Size
 CL depends on the size of the pupil.
Concentric or Annular Bifocal CL
o Can use regular fitting philosophy
 Assuming that the lens centers well.
 Can fit up to 6D steeper
o Central zone should be smaller than pupil
 Usually 3mm or less.
 Some larger if utilize both designs
o Usually fit as a simultaneous design, can be fit as an alternating design
o If designed as an alternating bifocal
 Need more movement (translation)
 Need larger central zone- so no simultaneous vision
o Advantages
 Not dependent on translation
o Disadvantages
 ~50% light available at each viewing distance, meaning decreased
VA
 Symptoms of glare, haze, halos, ghost images because the patient
sees 2 images at once.
 Dependent on pupil size.
Aspheric Multifocal CL
o F1 or F2 can be aspheric
 Majority are F2
 Made via blending various radii of curvatures (add effect by
adjusting TL)
o Higher eccentricity = higher add
 Gradual increase in plus towards the edge.
 Intermediate vision available
o Simultaneous or alternating?
 Dependent on eccentricity of lens
 Pupil size dependent
o Usually fit steep centrally; can be lid-attachment- Hi-Rider
 To get add effect and well centered.

 FP = AC
o Lens analysis
 BC- tilt radiuscope
 Looks like warp if youre not on the center.
 No distinct zones
 CLP- Schiener’s disc
 Pinhole it or use a smaller aperture
 Shift sideways to read add.
Eccentricity
Add Effect
0 (circle)
None
0.1-0.9 (ellipse)
Small (+1.00)
1.0 (parabola)
Medium (+2.00)
>1.00 (hyperbola)
Large (+3.00)
 This does not have the same result for every patient, because
patients have varying e values.
E
Steeper than K
Near Power Received
0.4
0.5F-0.5S
0.75D
0.6
1.5-2.75S
1.25D
1.0
3-3.5Steep
2.00D
1.4
4.75-6S
3.00D
 Increased e means increased near power, also steeper.
o Advantages
 Not as dependent on translation
 Intermediate vision
 More like “natural vision”
 Early presbyopes
o Disadvantages
 Add effect often not sufficient (decreased VA at near)
 Limited add capabilities based on parabolic/hyperbolic
manufacturing
 Add dependent upon pupil size.
 Critical near vision needs
 “Swim”
 Spectacle blur due to edema
Fused Crescent Bifocal- contains seg
o Distance vision in the superior portion of the lens. Near vision is in the
inferior portion.
o The lid must hold the lens in place. When the patient looks down, the lid
catches the lens, the lens moves, and the pupil looks through the inferior
portion. Doesn’t work well for those with floppy lids. Look at where the
lower lid hits the eye. If it is >1mm higher or lower than the limbus, the
lens wont work well for this patient. Most people fall within these
parameters though.
o A little nasal rotation is alright since the eyes converge to read. Temporal
rotation is bad.
o Fused crescent
o
o
o
o
 Add has higher n
Prism ballasted
 Most common
 So rotated properly
 Usually 1-3pd
 Add 0.10mm to center thickness for each 1pd.
 Selectively thin area you desire to position under upper temporal
portion of the eyelid (watermelon seed effect)
 Truncation may help stabilize rotation. It also drops the lens
 Shave off the inferior 2mm.
 Lower limbus should be tangent to lower lid (+/-0.1mm)
Segment
 Lens must catch on lower lid in downgaze
 Measuring the seg height
 Measure distance from visual axis to lower lid
o Slit lamp reticule
o Penlight at 20 inches while patient fixates the light.
o Subtract 1.3mm from the lower lid to visual axis
measurement
o –or- key off diagnostic lens.
Alternating design
 In theory
 Does BF drop fast enough so patient can see distance quickly?
 Don’t want to see both at the same time.
 Advantage
 Doesn’t block distance
 Disadvantage
 Smaller reading portion
 Who do you fit?
 Patients that want them
 Good for higher adds
 Previous wearers (don’t go to simultaneous)
 Not monovision patients
Types
 Many segment designs available: round (centered, decentered),
executive, upsweep, crescent, offset lenticular.
 Tangent streak (Fused Kontacts of Missouri)- trifocal
 Lifestyle Hi-Rider
 Aspheric
 Fit flat, vs steep like other aspherics.
 Fit as lid attachment. It behaves like a translating lens.
 It is a multi-aspheric back surface multifocal with a
progressive addition design.
 There are 2 kinds:
o Low add and high add.
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o Diagnostic set has a single aspheric surface. 10
lenses made of the SGP II material. The EQ values
range from 7.3-8.2mm and have 9.0 and 9.5 OADs.
The 9.5 is better to ensure lid attachment.
o High add has the same back asphericity, but an
additional front aspheric surface to increase the add.
(A +2.50 add is still rare).
Fitting
o Determine the patient’s flattest corneal reading
o Choose the EQ trial lens that is closest to this.
o Allow the lens to settle. It should assume the
superior position. 1/3 of the lens will be under the
superior lid with you looking through the distance
area during primary gaze.
o The lens should look flat when looking at the FP
(about 0.5D)
o If this does not work, try another lens that is 0.1mm
flatter.
o You should not go more than 2 steps flatter before
deciding that it doesn’t work.
o Performa sphero-cylinder OR.
Advantage
o It will work or not. There are no ifs, ands, or buts.
Disadvantage
o You will get an ortho-K effect, therefore this needs
to be the primary mode of eyewear. You cannot be
a partial lens wearer with this. The corneal
topography will change.
Case Example
o A 48 yo female RN with RGP monovision is not
happy. This means that she either 1. loves bifocals
or 2. will love monovision when you refit her. SO,
whatever you do will help make the patient decide.
o Refractions
 OD: -3.50 -0.75 x097 OS: -3.50 DS
 Add +1.75 20/20
o Ks:
 OD: 44.67 / 43.25 x180 Flat: 43.25 = 7.80
 OS: 44.37 / 43.50 x180 Flat: 43.50 = 7.76
o Trials: 7.80/-3.50 OU
o OR:
 OD: +0.25 _0.50 x090
 OS: +0.50 DS
o VA at 40cm: 20/25+2 – OU
o FP: AT x 0.75D/ Lid Attachment – OU

o F/U in 2 weeks and the patient complained of the
CL dropping after each blink. This caused an
unstable VA. A change to an EQ of 7.90 was made
and the CL power change accordingly.
o This is very common because it is seen in real
situations.
 Poor candidates
o Patients with poor lid tone
o Pupils greater than 5mm in ambient lighting
o Flat (<4100) and Steep (>45.00) corneas. It would
not be able to tuck under the lid.
Unilens RGP Aspheric
 Fit like your typical aspheric CL
 Patient selection
o Good motivation and realistic expectations
o Add up to 2.00D
o Up to 2.50 WTR or 0.75ATR so the lens can center.
o Current RGP wearer
o Patients with habitual prescriptions. (Myopes better
candidates)
 Fitting
o The BC should be set 1.50D steeper than K
o OAD
BC
OAD
Less than or = 7.2
9.2
7.25-7.95
9.5
Greater than 8.0
9.8
 A flatter BC requires an increased OAD to
“stick.”
o Fit centered, mid-peripheral alignment and slightly
central pooling. If decentered, choose a steeper BC
and look for improvement.
o With aspheric lenses, do not call it AT or AC. Talk
about pooling.
o Evaluate:
 With each blink does it recenter?
 With each blink do you have adequate tear
flow?
 OR
 Check NVA
 Compare CLP by OR to empirical CLP calculations
o DxCL
 CLP + ORv = SRx + (-1.25)
 Anticipate more minus power, because it is
fit steep on purpose.
o Double check the near VA with the final Rx

o With aspheric contacts, it is not rare to order
increased add to even the +1.25.
Blanchard Essentials
 Aspheric back surface
 Patient selection
o Existing RGP wearer
o Well motivated, reasonable expectations
o Presbyopic patients requiring sharp distance and
near
o Adds up to +2.75 (2.50 more realistic)
o Up to 2.50D WTR and 0.75D ATR
o Avoid very steep (>47D) or very flat K (<40D)
readings
o Avoid puils in excess of 5.5mm
 Comes in 3 series: 1, 2, and 3
o Each has a different power profile.
o Series 1 has a slower glide in power than series 3
which has a steeper and quicker glide in power.
Series 1 is better for new presbyopes (+0.75 to
+1.25 add), Series 2 (+1.25 to +1.75 add) and series
3 (+1.75 and up).
o It is not unusual in these aspheric bifocals that you
order a higher potential add power than what the
patient needs. For example, patient needs +1.25
add, youll probably stick them in a series 2 lens,
even though they are on the cusp of a series 1.
o The company supplies a BC and OAD selection
chart that the company recommends. Typically
these fitting guidelines have been put together by
many practitioners who have fit many of these
lenses.
 Lens position and movement
o The ideal fit will be superior central (upper lid
attachment) with a NaFl pattern that demonstrates
alignment along the flattest corneal meridian.
o This lens is very similar to a lifestyle hi-rider. The
lens position is not perfectly centered. It is more of
a slight lid attachment fit. So it is an aspheric lens
that behaves more like a simultaneous/translating
hybrid.
 Evaluation
o Perform OR with loose trial lenses to determine the
final distance Rx.
o Expect the final Rx to be -0.50 to -1.00D more than
the existing CLRx.



o Place the OR in a trial frame and evaluate the
transition form distance to near.
o If the OR leads to acceptable distance but stinky
near, rethink the BC or series design.
 Disadvantages
o The company is on the east coast, so there is a 2
week delivery time.
o Pretty pricey. ($140/lens)
Menicon SF-P Bifocals- Decentered target or crescent seg.
Fluoroperm ST- Paragon Vision Science
Solitaire- Tru-Form
 A segmented lens. The distance segment is cut above. It
looks like an executive bifocal. The plus bottom portion
acts like a carrier. It is like a tangent streak lens which has
an executive ledge and is thicker on the bottom because of
prism and truncatrion, so the tangent streak is more
uncomfortable. Also, because it is thicker inferiorly, you
get some physiologically breakdown of the inferior cornea.
This is rarely seen with the solitaire lens.
 A prismatic reading lens with a monocentric distance seg
cut on the top part of the lens using the same visual axis.
Because it is bottom heavy, you do not need as much prism
to stabilize it nor do you have to truncate it. This provides
for better comfort.
 Usually 2D of prism is sufficient, regardless of the CLP. A
good clinical tip is that you should always include 0.250.50D more prism that what the manufacturer recommends.
 Solitaire II has an intermediate corridor. The only issue
with this is that centration is of utmost importance.
 Fitting
o BC selection
 Very close to our fitting philosophy of K 0.75 (maybe 0.25-0.50 steeper)
Corneal Cyl
BC
Spherical
0.25 flatter than K
0.25-0.75D
On K
1.00D- 1.75D
On K to 0.25
steeper than K
2.00D-2.25D
0.50D steeper than
K
o Optic Zone Size
 OZ is 83% of the horizontal diameter before
truncation.
 Ex
 OAD 9.4  OZ 7.8
 OAD 9.0  OZ 7.5

o Seg placement and amount of prism will be the
toughest decisions.
o The visual performance is superior as long as the
seg is at the right location and is stable.
Troubleshooting
o Lens lags too long after blink
 Thin upper edge
 Increase prism
 Loosen lens, or order flatter BC
 Lower seg while increasing the diameter of
the new lens.
o Difficulty reading
 Patient not orienting head properly
 Lens too tight causing minimal movement,
loosen lens or order flatter BC
 Not enough clearance for vertical
displacement. High segment with smaller
diameter.
 Lower lid does not support lens, truncate to
produce more contact with lid.
 Order new lens with higher seg.
o Patient has trouble at distance
 If lens is not at lower lid, then loosen, order
flatter BC or lens with more prism.
 If lens positions properly, then seg is too
high. Truncate or order lens with lower seg.
 If lens is large, reduce diameter, and/or
truncate.
o Patient experiences flare
 Larger OAD and/or OZ for larger viewing
field.
 Lower seg to give larger viewing field.
Truncate or re-order.
 Patient has large pupils.
o Lens position too high
 Lens too tight, flatten
 Add more prism on new lens order.
 Diameter too small. If lens has truncation,
order new lens without or reorder larger
lens.
o Presbylite
 Intermediate blended
 Like a progressive
o Fitting
 Use diagnostic lenses
 Determine BC


o
o
o
o
Evaluate stability
Determine seg height
 Use a DxCL of an appropriate BC, find where the seg
height sits. In straight ahead gaze, the top edge of the seg
should ride at the lower edge of the pupil in ambient
illumination. Some manufacturers say to go about 1/3 into
the pupil, but most patients don’t like that. We are looking
for good stability of the inferior seg and good recovery
after blinking.
 Record amount of prism needed.
Best Case Scenario
 Better with RGPs
 Normal eyelid position should be within 1mm of the limbus. If the
lower lid is too high, it causes the segment to be in the way. If it is
too low, it means that the lens will not be shoved up for near
acuity.
 Average to small pupils are better. Too large means that the vision
runs into the near segement.
 Low WTR toricity (less than 2D). We want to lens to ride a little
low, so WTR allows us to do that. Rocking high means the seg is
in the way. Greater than 2D decreases comfort.
 High tone lid.
 Patient wants or is already an RGP wearer.
Lens Analysis
 BC- radiuscope, should be spherical (watch out for warp)
 CLP- use small aperture lensometer or blacken area of lens not
being measured with a visavis marker.
 Prism- use lensometer. Needs to be in the BD position.
 Seg Ht- use 7x
 If truncated, measure from the ideal bottom.
 It is more ideal if rotated due to convergence.
Advantage
 Crisp VA at both distance and near
Disadvantage
 Unable to meet vocational or avocational needs for upgaze
 Cant do adds on top (no double D)
 Not good for those with flaccid lids.
 Don’t fit
 Monovision patients
 Those with a lot of N
 Loose lower lids
Multifocal Soft CLs
 Translating Alternating Image Designs
o None in soft lens design
 Simultaneous Image Designs
o Types
 Concentric or annular segment
 Generally this works better in a soft lens modality, although
it can work in RGPs. It is a bull’s eye design. Distance and
near is seen at the same time in each eye. A common
complaint is a 3D effect when looking at something flat.
This makes sense because the near image is clear, then at
the same time the distance image is hovering right there too
so it is perceived as one object with the same one right
above it. Make the patient aware of this.
 Ciba, AV, CV, and Unilens are some brands that offer this
kind of lens. Unilens actually lets you choose a certain size
for the center zone. A smaller near zone on the distance eye
and a larger near zone for the near eye increases the success
rate.
 Annular
o Centrad (center-distance)
o Reverse centrad (center-near)
 Aspheric
 Posterior
o Behaves similar to PALs.
o Soft and rigid
o Posterior aspherics have a spherical front surface
o Increased power in the periphery. Much variety.
o Types
 Hydrocurve II (WJ)- CD
 Occassions (B&L)- CD
 CV Frequency 55 MF- CD and CN
 Sunsoft MF (Sunsoft)- CN
 Now FRP Sunsoft Additions.
 Anterior
o Soft CL Types
 Unilens (Unilens)- CN
 Softsite (Unilens)- CN
 AberCon N, N250, D (World Optics, Inc.)CN
o RGPs
 No add power added with these. The more
plus power require, means that one can
make both the front and the back aspheric.
Start with back aspheric, and can add to the
front if more plus required.
 Pupil size dependent.
 Diffractive
 Diffrax (RGP) or Hydron Echelon (OSI/American Hydron)
 Uses prism to create two images


 Seen more in Europe
Modified monovision
 SV in one eye/ bifocal in the other
Enhanced monovision
 2 bifocal of overlapping distance correction
o Brands
 AV Bifocal
 Simultaneous vision, concentric ring design (5 concentric
rings)
 Power range +4.00  -6.00 in 4 add powers
o The boxes are marked with 2 powers. The distance
and add.
 BC 8.5, OAD 14.2
 VT, inversion mark (123), UV block
 Often require increased minus.
 So thin that not so sensitive to inversion.
 Relatively good distance vision. Near is not so great.
 2 week less
 Focus Progressives
 Highly concentrated add power in a compact central near
zone.
 Large peripheral distance area
 2 week disposable modality
 8.6mm, 8.9mm BC
 OAD 14.0mm
 Vifilcon A, 55%
 +6.00  -10.00 in 0.25D steps
 Single progressive add; effective range up to +3.00
 Packaging in 6-packs
 Initial lens power selection
o SE + (Add/2)
o Example
 SRx = -2.00 with a +1.50 add
  -1.25
o a chart is available for this to be easier.
 condensed 2mm aspheric add zone right in the middle of
the lens. Since the add portion is small, distance area is
larger.
 CV Frequency 55 MF
 Methalfilcon A, 55% water, FW lens
 BC 8.7, OAD 14.4
 +4.00  -6.00
 Add powers of +1.50, 2.00, 2.50
 D lens (dominant), and a N lens (non-dominant eye)
 Modified monovision lens.




Aspheric design
o Fitting
 Use DxCLs for BC determination
 Lenses must center well. This is very important. Can go steeper to
center better for RGPs and can sacrifice the fit a little for better
centration.
 Allow the lens to settle at least 20-30 min.
 Perform trial frame or loose lens OR for BVA at 6m.
 Don’t use the phoropter.
 Make sure the patient is M+BVA
 Visual comfort more important than Vas.
 Test near VA with the same OR
Who should I fit with ?
o Motivated
o Realistic expectations
o “Spherical” subjective refractions
 Adaptation worse for toric bifocals
o Hyperopia greater than 1.00D
o Myopia greater than 2.00D
o No risk to try (Greater profit margin)
Best case scenario
o Large pupils to cover as much optics as possible.
o No critical vision tasks.
o Accept contrast loss
o Stable light environment
o Lenses must center
o Works best with soft lens design in general.
Disposable Soft Multifocal CLs
o Acuvue Bifocal
 Concentric design of 5 alternating zones of D/N
 “Pupil smart” because size independent
 1 BC
 SRvEDS- adds in 0.50D steps
 Loose lens OR +/- 0.25/0.50. No phoropter. This creates an
artificial environment
 Adjust D/N Rx as appropriate
o B&L
 Aspheric Soflens MF
 2 BC
 comes in high and low add
o Ciba Progressives
 Aspheric center near
 Also daily disposable
 1 BC
 ½ add + SRvEDS
 loose lens OK
 Efficient, comfort, handling
o Cooper Frequency 55 MF
 Aspheric
 Centrad/reverse philosophy
 D and N lens
 1 BC
 SrvEDS
 D lens: dominant/ N lens: non-dominant
 3 adds: +1.50, 2.00, 2.50
Seven Deadly Sins of Bifocal CLs
 Pick the wrong patients
o Don’t pick patients that are too meticulous about their vision, someone
with varied tasks, or too much cyl.
o Don’t be afraid to tell the patients that they are not good candidates.
 Omit trial lens fitting
o See how they center, move, translate, recover, and perform.
o Push max plus in the distance. Don’t overminus.
o Determine what the reading distance for the patient is. Use that as the
distance.
o Don’t worry about 20/20. just make sure the patient has the vision to do
everything that they need to do.
 Judge fit of the lens based on MOB alone
 Incorrect distance endpoint
 Over and under prescribing add power
 Not considering binocular performance
 Chasing perfection
Aspherics
 Aspheric Uses
o Reduce spherical aberration
 Decreases the CLC. For some, it therefore appears sharper or
clearer.
 No change in OR cyl.
o Improve fitting characteristics
 It contours to the eye.
 Easier A and R
o Provide add effect for MF designs
 RGP
 Blanchard Essential RGP MF
 Boston Multivision
 Lifestyle GP MF
 Unilens
 SCL
 SV
o Coopervision Frequency 55 Aspheric

MF
o Ciba Vision Focus Progressive
 Aspheric center add (~2mm)
o Unilens 38
 Front aspheric with near center



Aspheric Design
o Front surface aspheric
 Reduces spherical aberration
 Corrects residual astigmatism
 Additional add effects for MFs (a little)
o Back surface aspheric
 Continuous across entire F2- contours the cornea.
 Aspheric periphery (center spherical)- like a heavy blend
 Provides an add effects (“Main”)
 Continuous cornea
Advantages
o Better corneal alignment
 Yeah, but you don’t want it too good (poor a and r)
o Better centration
 On toric corneas (decreased centration with spherical corneas)
o Decreased spherical aberrations
o No junctions
 Increased blends, although nothing wrong with junctions
o Decreased flare
 Increased OZ because increased blends
o Increased comfort
 Only during adaptation. No long term effects
o MF effect, especially with new presbyopes
o K-cone and irregular corneal fittings
 Not good, because we don’t know the back curves, therefore we
cannot modify in-office.
Disadvantages
o Difficult to fabricate/polish/reproduce
 Uses a CNC (computer numeric control) lathe
 Cuts well, but the problem comes with polishing.
o Difficult to verify
 Use small aperture for CLP
 Increased aperture means increased plus power
 Tilt radiuscope to determine e value
o Variable vision
 Induce residual astigmatism with decentration
 Smaller “spherical” OZ with aspheric periphery might get only
4mm center.
o Lens decentration
 Means less VA due to increased plus power.





How to fit
o Front surface aspheric
 Less spherical aberrations means increased add effect
 Same base and peripheral curve fit (Normal fit)
o Back surface aspheric
 Fit steeper (need edge lift)
 Higher the e, fit steeper
 e usually 0.4-0.6 for fit (ellipse)- fit 0.5D steeper
 e > 1 for kcones and add effect (hyperbola) 3-5D steeper
 with e = 1, get 2D add
Marked Aspheric CLs- SV
o Boston Equivalent (B&L)- back surface precut by Boston
 Biaspheric F2 (low e in BC/high e in periphery- repeatable)
o Conforma E-Lens
 Spherical center with hyperbolic periphery
o X-Cel Starlens
 Spherical center with aspheric periphery
Marketed Aspheric CLs- Multifocal
o Power from F2 asphericity
o Blanchard Essential RGP Multifocal
o Boston Multifocal
o Lifestyle GP Multifocal
o Unilens
Marked Aspheric Soft CL
o Single vision
 CV Frequency 55 Aspheric
o Multifocal
 Ciba Vision Focus Progressive
 Aspheric center add (~2mm)
 Unilens 38
 Front aspheric with near center
Rules
o 0.1mm steeper = low  mod flattening (e)
o 0.2-0.3mm steeper = mod  high flattening
o can only fit with aspheric trials (Large BC increments- 0.1mm)
o consultation helpful. Follow fitting guide and learn from experience. Use
only 1-2.
o Front surface
 Center near
o Back surface
 Center distance
 e values > 1.0 (hyperbolic)
 Low add powers
 Centration helpful
o Multifocals
 May be considered simultaneous (majority) and translating design.
Presbyopia
 CL will work if patient is:
o Dependent on Srx
o Motivated
o Following instructions
o Possess discretionary funds
o Decreased corneal and lid sensitivity, due to lid lax
o May have long history of CL wear.
 Wont work if
o Decreased tear voume/quality due to hormones, meds, etc.
o More medications that might dry eye
o Fear of CL, anything touching eye if never worn before
o Decrased importance of cosmesis
o Medication interactions
o Decreased pupil size.
o Make sure that you establish realistic expectations
 Options
o Distance CL with near overcorrection, like OTC readers
 Example 1
 Patient Age 47- requires +1.50D add.
 SRv OD: -4.25 -0.50 x170
OS: -4.50DS
 CL Rx OD: -3.75
OS: -3.75
 OR
OD: +0.25 -0.50 x170
OS: plano DS
 FP
OU: AA/DS/Avg/C
o Prescribe near overcorrection
 +1.75 -0.50 x170
+1.50DS
Specify near PD
Specify on SRx for near use over the CL.
 Example 2
 Patient age 42 requires +1.00D add
 SRv
OD: +2.00 DS
OS: +1.50DS
 CLRx (D)
OD: +2.75
OS: +2.25
 OR (D)
OD: plano DS
OS: +0.25 -0.50 x090
 CLRx (N)
OD: +3.75
OS: +3.25
 OR (N)
OD: -1.00 DS
OS: -0.75 -0.50 x090
 FP
OU: AA/DS/Avg/C
o Prescribe distance spectacle prescription of:
 OD: -1.00DS
OS: -0.75 -0.50 x090
o Near CL with distance overcorrection. Good for those with a lot of
nearwork. Resembles young myopes.
o Monovision
 One eye is fit for distance, the other eye is fit for near.
 Simultaneous (distance and near)
 #1 presbyopic Cl option
 Only option for those with LASIK
 Success rate
o 80-90% (most successful fitting modality)
 Adaptation rate
o 15 min- 1 week depending on the patient. Average
about 3 days.
 Advantages
 Can use same fitting philosophies and lens materials.
 Can use same lens replacement schedule
 Less expensive than BF
 Don’t fit
 Patients who do mostly near or mostly distance work
 Patients with reduced VA in one eye (amblyopes)
 Fitting
 Selection of near eye
o Dominant eye for distance (most prevalent
philosophy) if most distance tasks are utilized.
o Vice versa if the dominant eye for near if do mostly
near work.
o Near lens for placement of vocational (typing) or
avocational (car mirror) needs
o If one eye has good unaided distance vision, fit
other eye for near.
o If one eye has good unaided near vision, fit other
eye for distance.
o For RGPs, fit both eyes because there needs to be
the same sensation.
 Near Stereoacuity
 Stereo is only needed with very detailed near work. No
monovision.
 Koetting (1970) found 94% of monovision patients had
normal stereopsis when age matched.
 Christie and Sarver (1971) found little or no loss of
stereopsis with adds of <1.00D.
 Blake, et al (1980) reported that a “suppressed” eye may
contribute to stereopsis.





McGill and Erickson (1988) reported reduction in
stereoacuity with monovision.
 This is a function of the add. Increased add means
decreased stereo.
Distance Stereoacuity
 Back (1987) found that monovision wearers exhibited a
significant loss in distance steresoacuity when compares to
soft bifocal CL wearers.
 Rouse et al (1988) found that static stereo deficient subjects
can use dynamically changing disparities to make depth
judgements.
Binocularity
 Loshin, Loshin, and Comer (1982) found that for adds up to
+1.50, binocular summation in contrast sensitivity function
was lost for middle frequency and high frequency (fine
detail). It was retained for low frequency. But, all binocular
summation was lost with adds greater than +2.00D.
Peripheral Vision
 McLendon et al (1968) tested VFs using a 3mm target.
They found that there was a decrease in the VF of 0.2
degrees for the eye corrected for near as compared to the
field of the eye corrected for distance. But, there was an
iveral increase of ~5 degrees for CL correction as
compared to spectacle correction.
o With monovision, 2-5 degrees are lost
 Lit, Stern, and Edrington (1991) found that adds <2.00D
had little or no effect on the binocular view. Subjects
demonstrated ~ a 2-5 degree field compression with adds
>2.00D
o Note that motion detection in the peripheral retina is
least affected by blur.
Legal Concerns
 Harris and Classe (1988)
o Altermatives need to be explained
o Limitations should be presented
o Have patient sign an informed consent
o Need to instruct the patient of adaptation.
o Caution against driving or operating heavy
machinery during adaptation to monovision.
 Nakagawa (2000)
o National Transportation Safety Board (NTSB)
determined that the probable cause of Delta aircrash
on 10-19-1996 was due to inability of pilot to
overcome misperception of airplane’s position
relative to the runway due to monovision.
 Slutsky, Wang, Edrington (2000)
o Pilot’s landing ability not related to distance stereo.
o Bifocal CL
 Alternating
 Analogous to SRx bifocals. 2 segs with 2 powers. Lens has
a small segment (3mm) and needs to translate. With large
pupils, one can have simultaneous vision.
 Simultaneous
 See distance and near at the same time (analogous to
progressives). Can also get an intermediate. Produces ghost
images and brain chooses which to see. Decreased VA a
little.
 RGP
 Concentric or Annular BF CL
o Can use regular fitting philosophy assuming that the
lens centers well. Can fit up to 6D steeper.
o Central zone should be smaller than pupil. Usually
3mm or less. Some are larger if utilizing both
designs.
o Usually fit as a simultaneous design. Can be fit as
an alternating design.
o If designed as an alternating bifocal
 Need more movement (translation)
 Need larger central zone so there is no
simultaneous vision.
o Concentric or Annular Segment
 Good
 Not dependent on translation
 Bad
 ~50% light available at each viewing
distance, reducing VA
 Sxs of glare, haze, haloes, ghost
images because we see 2 images at
once.
 Dependent on pupil size.
 Monovision: fit one with centrad,
other with reverse centrad. If you use
the same, the VA is usually not as
good.
 Aspheric MF CL
o F1 or F2 can be aspheric. Majority are F2.
 Made via blending various radii of
curvatures. There is an add effect by
adjusting the tear lens.
o High eccentricity = high add. There is a gradual
increase in plus towards the edge. This gives an
intermediate vision as well.
o Simultaneous or Alternating?
 Dependent on eccentricity of lens
 Pupil size dependent
o Usually fit steep centrally: can be lid-attached (i.e.
Hi-Rider). This is to center the lens and get an add
effect.
o Lens analysis
 BC- tilt radiuscope
 Looks like warp if youre not on the
center
 No distinct zones are seen.
 CLP- Schiener’s disc
 Pinhole it or use a smaller aperture.
 Shift sideways to read add.
Eccentricity
Add Effect
0 (circle)
None
0.1-0.9 (ellipse)
Small (+1.00)
1.0 (parabola)
Medium (+2.00)
>1.0 (hyperbola)
Large (+3.00)
Note that the add effect is not the same on every patient due to the
varying e values.
o Good
 Not as dependent on translation
 Intermediate vision, more like “natural”
vision.
 Early presbyopes
o Bad
 Add effect often not sufficient (decreased
VA at near)
 Limited add capabilities based on
parabolic/hyperbolic manufacturing.
 Spectacle blur due to edema.
 Add dependent upon pupil size
 Critical near vision needs, “swim”
 Fused Crescent BF
o These all contain a seg.
o Fused crescent
 Add has higher n
o Prism ballasted
 Usually 1-3D
 Add 0.10mm to ct for each 1pd.
 Selectively thin area you desire to position
under upper temporal portion of the eyelid
(watermelon seed effect)
 Truncation may help stabilization rotation. It
also drops the lens.

o
o
o
o
o
o

SCL


Lower limbus should be tangent to lower lid
(+/-0.1mm)
Segment
 Lens must catch on lower lid in downgaze
Alternating Design
 In theorey
 Does BF drop fast enough so patient can see
distance quickly?
 Don’t want to see both at the same time.
Lens Analysis
 BC- radiuscope, should be spherical (watch
out for warp)
 CLP- use small aperture lensometer or
blacken area of lens not being measured
with a visavis marker.
 Prism- use lensimeter. Needs to be in a BD
position
 Seg Height- use 7x. if truncated, be sure to
measure for the “ideal” bottom. More ideal
if rotated due to convergence.
Advantage
 Crisp VA at both distance and near
Disadvantage
 Unable to meet vocation or avocational
needs for upgaze
 Cant do adds on top (no double D)
 Not good for those with flaccid lids.
Don’t fit
 With monovision patients
 Those with a lot of near tasks
 Loose lower lids.
Translating Alternating Image Designs
o None in SCL design
Simultaneous Image Designs
o Concentric or annular segments
 Acuvue BF
 Concentric design on 5 alternating
zones of distance and near.
 Pupil smart, because size
independent
 1 BC
 SRv EDS- adds in 0.50D steps
 Loose lens OR +/- 0.25D. Do not use
the phoropter. It creates a false
environment

Adjust D/N Rx as appropriate.
o Aspheric
 B&L
 2BC
 Comes in high and low adds
 Ciba Progressives
 Also daily disposable
 1BC
 ½ Add + SRv EDS
 loose lens alright.
 Efficient, comfort, handling
 Cooper Frequency 55 MF
 1BC
 SRv EDS
 D lens: dominant in center
 N lens: non-dominant in center
 Centrad/reverse philosophy
 In 3 adds: +1.50, +2.00, +2.50.
o Diffractive
 i.e. Diffrax or Hydron Eschelon.
 Uses prism to create 2 images
 Used more in Europe
 Who should I fit?
o Patients with
 Motivation
 Realistic expectations
 “Spherical” SRs
 Adaptation is pretty bad for toric
bifocals
 Hyperopia greater than 1.00D
 Myopia greater then 2.00D.
o Modified/ Enhanced Monovision
 Modified- 1 SV CL and 1 Bifocal
 Enhanced- can overlap Rxs. Distance/intermediate and
Intermediate/Near.
o All options are available with either RGPs or SCL
 The problem with the SCL and translating designs is that it is not
available because it is too large to translate.
Clinical Myopia Control
Methods of Treating Myopia
 Spectacles
 CL

o SCL
o RGP
Surgery
Myopia Control
 Bifocals
 Pharmaceutical Agents (Atropine)
 CL (RGPs)
o The Possible Influence of CL on Myopia (Stone)- 1976
 London Refracting Hospital, n = 150 (120 after 4 years)
 80 patients in CL (8.5-16.5yo)
increased -0.50D
 40 patients in SRx (6.5-16yo)
increased -1.75D
o Refractive Stability of CL Wearers (Brungardt and Brungardt)- 1980
 13-30yo; 12-42mo.
 74% no change while wearing CLs. When cornea flattens other
components change inversely so that refractive error usually
remains unchanged. They infer that a like sample of SR patients
would show no change.
o Attempts to Reduce the Rate of Increase of Myopia in Young People
(Goss)- 1982
 Criticism
 CLs used at older age = myopia stabilization
 CLs tend to over correct the required minus power so that
myopia could increase before a measured drop in VA with
lenses
 Corneal flattening induced by CLs decreased refractive D
of the eye.
 None of the many different theories have been shown to be
consistently effective in reducing the rate of increasing
myopia.
o Variation of Refractive Error During the First Year of CL Wear
(Hovding)- 1983
 SCL wearers demonstrated an increase in myopia
o Is Myopia to be Controlled by Wearing CL? (Kemmetmuller)- 1987
 Law of functional adaptation
 20,673 CLs 72.05% no change in refractive error.
 25,639 SRs 24.01% no change in refractive error.
o The Role of Bifocal and CL in Myopia Control (Grosvenor and Goss)1988
 Silicone Acrylate Lenses on 9-13yo after one year
 58 CL increased in myopia by
-0.06D
 10 part time wearers increased by
-0.60D
 24 controls increased by
-0.43D
o Use of Silicone Acrylate CL for the Control of Myopia: Results after 2
years of Lens Wear (Grosvenor, Perrigin, Perrigin, and Quintero)- 1989
 After 2 years of CL wear

o
o
o
o
o
o
o
o
100 children (8-13yo), after 2 years, n = 60.
 58 full time increase in myopia
-0.28 +/-0.60D
 7 part time increase in myopia
-0.93 +/-0.54D
 31 SR increase in myopia
-0.80+/-0.77D
 Only half of the mean stabilization of myopia is due to corneal
flattening.
Silicone Acrylate CL for myopia Control: 3-Year Results (Perrigin, et
al.)- 1990
 n = 56 CLs
 Increase in myopia
0.48 +/- 0.70D
 SR increase in myopia
1.53 +/- 0.81D
 Corneal flattening accounts for < ½ of power change
Long Term effects of hydrophilic CL on myopia (Andres)- 1990
 SCLs have no affect on myopia progression although other reports
describe phenomenon of “myopic creep.” This is not validated.
Use of CL in Progressive Myopia (Shapiro, Kivaev, Kazakevich)
 n = 535
 385 RGP wearers no change in
73.4%
 150 SR wearers no change in
10.8%
RGP CL for Myopia Control: Effects of Discontinuation of Lens Wear
(Perrigin, Perrigin, Quintero)- 1991
 Effect of RGPs on myopia progression is diminished if lens wear is
discontinued, however it is still less than if SR only was worn.
Do RGP Lenses Control Myopia Progression? (Grosvenor)- 1991
 Is a diffence of 1.00D worth it?
A 3-year Study on the Effect of RGPP CL on Myopic Children (Khoo,
Chong, Rajan)- 1999
 There was a decrease in the progress of myopia in children
wearing the lenses compared to children wearing spectacles. For
effectiveness, lenses needed to be worn about 8 hours a day.
 n = 105 (10-12yo with >1D myopia and <3D cyl)
 RGP: 1.26D decrease in myopia, K flattened 0.45D, axial
lengthened 0.66mm.
 SR: 2.34D increase in myopia, K flattened 0.21D, axial lengthened
0.93mm.
Correction of Myopia Evaluation Trial (COMET) (Gwiazda, et al)- 2003
 A randomized clinical trial of PALs vs. SV on the progression of
myopia in children
 Use of PALs slowed the progression of myopia by a small amount
during the first year of study compared to the SV group.
 Increase of myopia of -1.28 +/- 0.06D in the PAL groupand
-1.48D +/- 0.06D in the SV group.
 The 3 year progression difference was 0.20 +/- 0.08D between the
2 groups.
CL and Myopia Progression Study (CLAMP) (Walline)
 No current published data
 Large dropout rate; 80% success (8-11yo)
o Prenzipine Study (PIR) (FDA)
 This is studying pharmaceutical intervention.
 Pirenzipine is put out by Novartis as an ulcer medication. It is a H1
selective muscarinic antagonist, causing decreased accommodation
and no dilation.
 Glaucoma medications and enzymes are also being studied. They
think that glaucoma medications would decrease IOP, and would
decrease axial elongation. Enzymes tighten and prevent tissue
expansion.
o Singapore and Taiwan Myopia Progression Study (Leung and Brown)1999
 Progression of myopia in Hong Kong Chinese schoolchildren is
slowed by wearing PALs.
 Mean increase in myopia, over 2 years, for SV group (n=32) was
1.23D, those wearing +1.50 add (n=22) was -0.76D, those wearing
a +2.00 add (n=14) was -0.66D.
o Conclusions
 Only Baldwin’s paper says that there is no change.
 Walline- 2001
 Commented on all studies
 No control group in any and subject loss
 Only 2 studies looked at axial length (Baldwin and Khoo)
 What about dropouts?
 What about age (>16yo)- CL were utilized at any age
where myopia stabilizes.
 CL overcorrect minus power, therefore myopia could
increase before a measured drop in VA with lenses.
 Increase in myopia late in life usually due to change in axial
length, not the cornea.
 Studies with bifocals not as strong as CL.
Orthokeratology


What is is?
o This is a programmed replacement of lenses/ part time wear to reshape the
cornea with the intention of decreasing refractive error.
o This drops the e value back to 0, creating an oblate cornea
o Squeezes the epithelium centrally with peripheral swelling.
Background
o Early Chinese applied small bags of sand on eyelids overnight changes of
the cornea occur with CL wear.
o Bates Method- Palming
o Causative Factors
 Lens-cornea bearing relationships

 Lens diameter
 Center thickness
 Mass
 Position (***)- most causative
 Duration of wear
 Lid tension
 Role of blink
o Other Considerations (little predictive values)
 Tensile strength of the cornea
 Ocular rigidity
 IOP
 A very low IOP does not hold the shape of the cornea.
 An increased IOP means a decreased success with OK)
 Individual tissue response.
o Jessen was the first to do OK with the suggestion that the BC should be
changed so that the LL compensated in power for the refractive error. This
is basically the premise of the Ortho Focus technique.
Research
o Bottom Line
 Variability; corneal flattening didn’t agree with BC flatness. The
flatter the fit, the greater the variability.
 Position of the lens is important (centration)
 Induced WTR astigmatism
 OK is an individualized process.
 It is best done at night
o Fitting Philosophies (All are successful to some degree)
 Jessen Method (62)
 Plo lens, tear lens corrects myopia
 i.e. a 1D myope would be fit 1D flat.
 Tabb Method
 Slight ACT fit with an aspheric periphery. Some flattening
is still obtained.
 Gates Method (71)
 1.50 flat
 Nolan Method (72)
 1-1.50 steep
 Fontana Method (72)
 Central bearing of 6.0mm, one piece lathe cut bifocal.
1.00D flatter in the paracentral zone.
 Freeman Method (74)
 0.50-1.00 flat
 Zift Method (76)
 On K- 1.00D flat
 Shed Method
 Tangent touch on the flattest K (usually 0.50 flat)
 May-Grant Method (MGM) (77)


0.50D progressively flatter until +0.50 CLP
conventional tricurve RGP with BC fit slightly flat (0.501.00D AT)
 Jenkin Method
 Slightly steep fit
 Paige Method (81)
 Plus Lens Increment (PLI) fit BC such that CLP will be
+0.75D.
 Harris-Stoyan Method (92)
 1.00-1.50D flat, SCr is steeper than BC
 Mountford Method (97)
 Driem Method (97)
 Wave-theorey Method
o Modern OK
 Corneal Refractive Therapy (CRT) (00)
 Similar to Jessen method, use of sigmoid reverse curve and
landing zone to maximize effect.
 This was the first approved overnight use.
 Terminology
o Reverse Zone Depth (RZD)
 Depth of the secondary curve
 Affects sagittal height
 550 microns (steep) to 450 microns
(shallow) means that there is a decreased
sag, meaning that it is flatter.
 If the RZD is too deep and lifts the treatment
zone, it is called bridging.
o Loading Zone Angle (LZA)
 Alignment curve
 Want even alignment.
 Toe down- too close
 Heel down- can lift lens
 Tangent- ideal.
 Paragon CRT (01)
 Reverse Geometry
 Flat BC
 Steep secondary curve
 Indicated to improve lens centration
 Use when calculated secondary curve is steeper than the
BC
 Good fit minimizes areas of excessive bearing or pooling.
 Seen in both RGPs and SCLs (B&L SL66/ FlexLens)
 First generation- Accelerated
o Topographical changes





Next generation- Advanced- dual tear reservoir,
compensated aspheric dual surface
o For OK and post-sx.
Orthofocus
 BC fit flat enough so that the TL compensates the power of
the refractive error.
Corneoplasty
 This is used in conjunction with OK.
 Vitrease (Hyaluronic acid), an enzyme, is injected into the
stroma with reversing drops so that the shape is held. It has
a proposed longer duration of the OK effect during the
retainer phase.
Terminology
o BC
o Secondary Curve; reverse curve, reverse zone depth
o Third Curve; alignment curve, return zone, landing zone
o Fourth Curve; edge lift
Fitting
o Patient selection
 Motivation (min VA requirement vs. “tired of glasses”)
 Patients expectations- realistic?
 Time frame: ~30 days to hold/maintain stability.
o Patient Education
 Time commitment- maybe >1 CL to mold K. A lot of chair time.
 RTC: 1 day, 1 week, 2 weeks, 1, 2, 6, 9 mo, 1 year.
 Financial Commitment- expensive.
 No guarantees, no refunds. OK is very difficult to predict.
o Preliminary Testing
 Thorough case history to include information discussed above.
 Establish baseline
 Unaided VA
 Corneal measurements (keratometry and topography)
 Refraction (objective and subjective)
o Diagnostic CL Fitting
 CRT
 Take flat Ks, flatten by magnitude of refractive error and
add extra 0.50D fudge factor so that the CL does not pinch
the K.
o i.e. Ks 45.00 @ 180, 46.00 @ 090. Rx = -3.50.
 Flat = 45.00  7.50
 -3.50 x 0.2 = 0.70. Add to flat K.
 7.5 + 0.7 = 8.20.
 Add +0.1 for correction = 8.30.
 For emmetropia, all corrected for +0.50 sph
 Tables available.
o Flat K  mm
o Rx sphere  mm
o Add 1 and 2
o Add 1mm.
 Conventional Lens Design (Tricurve)
 A lens that is progressively flatter. The SCr is flatter than
the BC
 Determine optimum fit (AA, MBA)
 Order BC 0.50-1.00 flatter than optimum fit
 Use mid to high Dk lens material
 Greater center thickness to facilitate OK effect. Possibility
that this induces cyl?
 Accelerated Lens Design (Reverse Geometry)
 Multiple curves. OZ 6-7mm, SCr = 2nd OZ.
 Decreased centration, increased K distortion, steeper
secondary curves, fit 2D flatter than flat K, steepend
secondary curve to fit flatter (and increase OAD)
 Secondary curve is ~3D steeper than BC
 Diagnostic fitting is imperative
o Select lens that is 1.50-2.00D flatter than flat K
o Appropriate lens fit will have central bearing area of
4-5mm, mid-peripheral pooling (2-3mm wide band)
and lens movement of 1-2mm.
o Lens centration is important.
 This method is faster than standard OK.
o 1-3mo (vs. Standard: 9-16mo)
 Advanced Lens Design (4 Zone Lenses)
 This changes the cornea from prolate to oblate.
 Secondary curve is steeper than BC or use of sigmoid curve
(2-12D steep)
 Integration of topography and computerized calculations
o Lens BC similar to Jessen method of BC selection
o SC determined based on eccentricity measurements
and/or HVID
o Fit looks similar to Accelerated design, centration is
important.
 Fudges to give a hyperopic shift to increase time without
SRx.
 Dual Tear Resevoir
 Use angles and curves to create an elevation.
 For advanced myopia.
o Changing Lenses
 Normally use 1
 Changing 0.1mm is equivalent to a flattening of 0.5D.
 Secondary curve shallow makes fit shallow and drops it closer to K
by 21 microns.
o
o
o
o
o
 Changing BC alters only by 7 microns
 Chaning LZA changes it by 12 microns.
Dispensing and Follow-up
 Dispensing is no different than any other RGP lens.
 Wear schedule
 Gradual increase in wear time if no previous lens wear
 The longer the wear time, the greater the effect
o Overnight
 The risks are the same as any RGP overnight
wear.
o Day wear
 Test at Follow-up
 Aided VA
 OR (Should be plano to +0.50)
 Fit assessment
 Unaided VA
 Corneal measurement (keratometry, topography)
 Refraction (objective and subjective)
 Corneal health assessment
 As refractive changes occur lens changes are necessary
 Old: change 0.25-0.50 flatter
 CRT: modify RZD/ LZA
Retainer Lens Wear
 Now, basically wear the same lens throughout, or the last lens fit.
 Retainer lens selection
 Retainer lens wear schedule. Comfort level of doctor and patient.
Modern OrthoK
 Aka PCM (Precision Corneal Molding), CKR (Controlled
KeratoReformation), or CRT (Corneal Refractive Theraphy).
 Accelerated OK
 Reverse geometry lenses
 Topographical changes
 Advanced OK
 Dual tear reservoir reverse geometry lenses
 Overnight applications
 Driemlens
Terminology
 Base curve
 Secondary curve; reverswe curve, reverse zone depth
 Third curve; alignment cuyrve, return zone, landing zone
 Fourth curve; edge lift
Corneoplasty
 Intrastromal injection of an enzyme
 orthoK lens wear

proposed longer duration of orthok effect during retainer phase (3
mo).
o Benefits of Topography
 Selects good candidates. No irregular Ks.
 Follows change with time.
 Central islands
 Bridging with poor fitting OK RGPs
 Steep fitting response.
 Causes: Large OAD, too deep RZD, landing zone too high
 Smiley Face
 Flat fitting response
 Inferior paracentral arcuate distortion (IPAD)
 Decenters.
 Due to: decreased OAD, RZD too shallow, LZA too flat.
 Bull’s Eye: Ideal
 Centered concentric area of flattening
 Ring of midperipheral pooling
 Want uniform corneal power over visual axis
 Need 10 microns TL between CL and K
Keratoconus
 Definition
o Keratoconus is a progressive, noninflammatory ectasia (bulging) resulting
in thinning, protrusion, and distortion of the central cornea. It occurs a
little inferior, but can be located anywhere.
o Results in irregular astigmatism
o Bilateral and asymmetric
 Average 4D
 1.5-2 line difference (3D in Rx)
o women = men
 Patient Education
o Not going blind
o No LASIK
o Don’t rub eyes
o Have a family
 Diagnostic Signs
o Fleischer’s Ring
o Vogt’s Straie
o Corneal scarring
o Shows up well with DFE. Look at the red reflex.
o See bulging with optic section of SLE.
 Onset/Course
o At puberty or later
 Stabilizes in 3rd/4th decade?


o The average self-reported age of diagnosis in the CLEK Survey (n=1579)
was 27.3 +/- 9.5 years
o Theory that the younger the age of onset, the more progressed the disease
becomes.
o Penetrating keratoplasty is indicated when the patient can no longer
tolerate contact lenses or the BCVA is reduced (generally due to corneal
scarring).
 Even with success, there can be a period of time before the final
VA is achieved.
 More than half still require CL to overcome residual astigmatism
or myopia.
o 5% of patients (73 eyes of 63 patients) who enrolled in the CLEK study
with no corneal transplant have undergone PK in one or both eyes in 4
years.
o The severity of the condition and the treatment method depends on how
steep the cornea is, the visual performance, the duration of the disease, the
condition of the fellow eye, and how bad the clinical signs in an eye are at
presentation.
Incidence and Prevalence
o Average annual incidence of 2:100,000 (Kennedy, et al.)
o Prevalence rate of 54.5:100,000 (Kennedy et al.)
o Prevalence rate of 370:100,000 (Hofstetter)
o 56% male in CLEK study (n=1209 kcone patients)
Etiology
o Hereditary
 13.5% of CLEK patients had a family history of kcone
 suspect AD inheritance pattern with variable penetrance of the
gene.
o Endocrine
o Collagen
 Increase in stromal intercellular substance and a decrease in total
collagen, accompanied by an increase of structural glycoprotein
component.
o Eye Rubbing
 48% of CLEK patients reported rubbing both eyes vigorously and
2% reported rubbing only one eye vigorously. (3.2% unsure)
 could this possibly release an enzyme in the stroma causing
thinning? The kcone corneas have decreased levels of enzyme
inhibitors and increased enzyme activities that can degrade the
various extracellular matrices within the corneas. This imbalance
results in stromal thinning and Bowman’s membrane breaks seen
in kcone corneas.
o Apoptosis
 It is caused by chronic epithelial cell damage from eye rubbing and
CL wear, increased levels of LAR and decreased levels of TIMP-I.
o Oxidative damage




Within the kcone corneas, there is an accumulation of reactive
oxygen species that results in deposits of cytotoxic byproducts
(MDA and peroxynitrates) that can damage the corneal tissues.
The cells that are only partially damaged by oxidative stress
undergo the process of wound healing. This increase in wound
healing causes local areas of fibrosis and scarring close to the
Bowman’s layer of the cornea.
o Previous rigid CL wear
Associated Diseases
o Atopic disease, such as hay fever, allergy, asthma, or eczema
 52.9% of the CLEK patients had hay fever or allergies, 14.9% had
asthma, and 8.4% had atopic dermatitis.
 10-20% of the general population of atopic disease
o No patients at baseline in the CLEK study reported a history of Down
Syndrome, Marfan Syndrome, focal dermal hypoplasia, Ehlers-Danlos
syndrome, infantile tapetoretinal degeneration, oculodentodigital
syndrome, osteogenesis imperfecta, or Rieger’s anomaly
Symptoms
o Decreased vision and/or visual distortion at distance and near
o Monocular diplopia (or multiple images or ghosting of images)
o Frequent spectacle changes without much improvement
Signs
o Retinoscopy
 Irregular reflex with accompanying scissors motion
o Manifest Refraction
 High amount of astigmatism
 Often oblique astigmatism (or ATR)
 Often high myopia (although many are hyperopic)
 Poor endpoints and repeatability
 58% of eyes in the CLEK study had >20/40 VA through manifest
refraction. 88% had 20/40 or better with CLs. Average is about
20/25.
 Fudge more towards the minus.
 Patient ed that the rx can fluctuate.
o Keratometry
 Steepening
 Axes not 90 degrees apart
 With >46D or large change, do topography.
 Distortion
 Does not clear with blinks
 More pathognomonic than steep Ks.
 Mean flat K was 49.49 +/- 6.01D in the CLEK study
 18.3% of CLEK patients had K readings flatter than 45.00D
o Biomicroscopy
 Thinning and protrusion of the cornea, usually inferior/central
 Up to 1/5th of normal corneal thickness.




Thickening of the corneal nerves.
Hydrops due to descemet’s membrane rupturing and
aqueous flowing into the cornea.
 Reduced IOP? (False low)
 Vogt’s Straie
 Usually vertical, fine, white lines fanning around the base
of the cornea.
 They are subepithelial fibrillary lines resulting from the
outward bowing and thinning of the ecstatic cornea.
 Disappear with pressing on the eye.
 65% of CLEK patients had striae in one or both eyes.
 Fleischer’s ring (full or partial)
 Formed from hemosiderin (iron) pigment deposited deep in
the epithelium. As the ectasia progresses, the ring tends to
become more densely pigmented, narrower, and may
become complete.
 Broken down circle at base of cone.
 Seen better with DFE.
 86% of CLEK patients had this ring in one or both eyes.
 Scarring- from condition (wound healing or eye rubbing) or poor
fitting CLs
 53% of CLEK had scarring in one or both eyes.
 Munson’s Sign
 Not diagnostic (only seen if very bad)
 Look down and lower lid distends.
Instrumentation
o SLE
 Detect corneal signs.
o Handheld keratoscopes (Placido’s disks)
 Early kcone is characterized by a downward displacement of the
horizontal axis of the Placido disk.
o Computer-assisted videokeratoscopes
 The most sensitive device for confirming the diagnosis of
keratoconus. This device generates color-coded maps and
topographic indices. Keratoconus appears as an area of increased
surface power surrounded by concentric zones of decreasing
surface power.
o Pachymetry
 This instrument can be used to help confirm the diagnosis of
keratoconus but it cannot be used as the only method to make the
diagnosis because of the large range and variation of pachymetry
readings both centrally and paracentrally in the normal population.
o Keratometer
DDx
o Keratoglobus, Pellucid Marginal Degeneration, Terrien’s Marginal
Degeneration, Marginal Furrow Degeneration
Management
o Fit to enhance or improve vision, not to slow progression of keratoconus.
o Eventually RGPs are the best. Transplants are the last resort.
 Contact Lens Options
o The use of contacts

 “Ideal” RGP Keratoconus Fit
o Sagittal height of BC to equal or slightly exceed the sagittal height of the
cornea for the same chord diameter (not too steep/flat)
o No excessive areas of tear/debris pooling underneath OZ
o Good exchange of tears
o Average PC.
 Keratometry
o Readings are difficult, yet these are better than topography.
o Extend range by utilizing a +1.25D spectacle trial lens and adding 9D to
the drum reading. Add this on the patient’s side. Can also add +2.25.
o Use steep K only as a starting point for selection of diagnostic CL.
o Axes not necessarily 90 degrees apart.
 Fit by FP
o Goal is slightest amount of apical clearance or feather “three-point” touch.
This is the steepest flat fot. In general, get a slight AT. Always bearing on
a slight raised area.
o Goal is to minimize areas of mid-peripheral tear pooling and around base.
 Treat by decreasing the OZ
 Can lead to dimple veiling.
o Goal is to obtain average PC
 Err on side of too much (max>min)
 Research
o Korb, Finnemore, and Herman (82)
 n=7
 One eye fit AT, the other AC x 1yr.
 Results:
 4/7 flat developed scarring
 0/7 steep had scarring.
 Problem: its an asymmetric disease, so cant compare, too many
variables, n =7.
o CLEK
 12% fit AC
 88% fit AT
 <45D
1.18D flat
 45-52D
2.38 flat
 >52D
4.01 flat
 Average 2.86 flat, sd = 3.31


 Conclusion: scarring is due to degree of flat fit.
Lens Parameters
o BC radius is determined by FP analysis
o CLP is determined by overrefracting endpoint diagnostic CL and adding
OR-EDS to power of diagnostic lens.
o OAD is generally smaller than for cosmetic orders, for example, 8.6mm.
o OZD is usually smaller, i.e. 5.5-7.0mm. Smaller OZ sizes used with
steeper BCs.
o SCr is flat relative to generally steep BCs. SCR should generally be
ordered in the range of 8.00-8.50mm.
o TCr/w is standard, i.e. 11.00mm/0.2mm.
o ct is generally in the range of 0.10-0.13mm due to the high minus CLP
encountered. For lesser minus orders, thickness should be increased due to
the extra removal of edge material necessitated by the flatter SCr.
o Material should be RGP. Currently we recommend FluoroPerm 30. Avoid
lenses with UV inhibitors due to decreased ability to interpret FPs.
o Blend (medium) junction between BC and SCr with a radius tool
approximately half way between the BC and SCr.
o Ex
 BC
6.50mm (51.92D)
 CLP
-9.50D
Heavy minus. No correlation
between the CLP and SRx.
Increased + TL.
 OAD
8.6
Smaller better
 OZ
6.5
Decreased for increased
centration. To decrease
flare/glare, go to 5.5.
 SCr
8.5
0.7 flatter than BC is way too
tight. Judge with FP.
 TCr/w
11.0/0.2
standard
 Ct
0.14
Flexure not a concern. Fudge
Thicker.
 Blend
Medium
need a good blend.
 Material
Dk30
decreased Dk to help
Modification. Specify no UV.
Trouble-shooting
o Decreased Wearing Time
 Problem Cause:
 Binding of peripheral curve system leading to decreased
tear pumping
 Recommended Treatment
 “open up” PC system, i.e. flatten SCr or further blend.
Note: laboratories oftentimes “correct” your order,
therefore secondary curves you receive for your Kcones
can be steeper than ordered.


o Stippling Staining around the base of the cone
 Probable Cause: excessive midperipheral pooling of metabolic
debris.
 Recommended treatment
 Decrease OZD
o Coalesced, Abrasive Staining at Apex of Cone
 Probable cause: mechanical
 Recommended treatment: if AT, order steeper BC.
Helpful Hints
o Avoid toric designs unless peripheral fitting relationship indicates need.
o Correct residual (oblique) cylinder with a spectacle overcorrection.
o For 3-9 Staining
 Treat with copius lubricants
 Piggyback with disposable (-0.50 AV/ Ciba N&D)
 The night and days are more expensive and rip easier with
RGPs.
 This is only a temporary solution.
 Worry only of the condition worsens or coalesces
www.nkcf.org
Pellucid
 Use SCL if VAs are still good (early)
 With RGPs, fit superior cornea (large OAD)
o Will have a lot of AT (happy medium)
o Inferior bulge, so the CL will ride low.
 Management
o Soft Toric
 Too thick inferiorly- neo concerns
o SoftPerm
 Good vision, good comfort, good centration, but poor physiology:
center has a Dk of 13 and carrier has a Dk of 5.
 The center can also rub and irritate the cornea.
o RGPs
 K-conus design- lens may position inferiorly
 Lid attachment- inferior edge lift may pop lens out
 Large OAD- good idea
 Covers the visual axis
 Good centration
 Good stability
 Dyna Intralimbal by Lens Dynamic
o 11.2 OAD, 9.4 OZD, steep, standard, or flat PC
system. No BC is indicated.
o 3-9 staining problems
o this is now available in reverse geometry design
(2D, 3D, and 4D steeper than BC)

o custom always possible
Other large lenses
o Jupiter (Innovations in Sight)- 15mm
o Macrolens Einstein (C&H)- 15mm
Fitting the Post-surgical Cornea
 Post-surgical indications
o Penetrating Keratoplasty
 Graft Considerations
 Steep grafts
 Flat Grafts
 Tilted Grafts
o Same as irregular cornea
o Large OAD
 Proud
o Sphere
o Aspheric
o Fit-like keratoconus
 Sunken/Plateau
o Graft and host same size
o Reverse geometry
 Eccentric
o Same as irregular cornea
o Large OAD
 High Cylinder
o If irregular, fit sphere
o If cyl is corneal and no corneal distortion is present,
RX bitoric.
 Main considerations
 The size of the graft
o Keep OAD within limits of the graft
 The tilt of the graft
o Lens decentration and stability
 Lens Stability
o Increase OAD (>12mm)
 Staining of grafted tissue
o Careful observation/ unacceptable
o Chronic staining into the cornea may be an early
sign of graft rejections. Refer back to the corneal
specialist.
 1-3 mo post-op is highest risk.
 Watch for: pain, redness, blur, and increased
light sensitivity.
 Sutures
o Running, interrupted, or combination.
o This is a preference of the surgeon
o Watch for broken sutures.

CL Fitting
 Up to 50% of post-PK patients will benefit from CL wear.
 Over 50% of post-PK patients have 4 or more D of
astigmatism.
 Irregular astigmatism is common
 Fit 4-6mo post-sx.
 May RX soft if irregular astigmatism is minimal.
 Prefer silicone hydrogels, avoid toric SCL.
o Post cataract surgery
 Aphakic lenses (RGP)
 Small centering lenses
 Large lid attachment lenses
 BC = avg to steep K for centration
 OZ depends on pupil size/shape.
 Because these can be very thick, there needs to be an
increased Dk.
 IOL still the best route.
 Problems with RGPS
o Ejection, because small and heavy
o Displacement
o Temporal ride. Falls down and out.
 Aphakic Lenses (SCL)
 Fit conventionally
 Medium water DW, high water EW
 Problems with SCL
o Ejection
o Displacement (<RGP)
o Visual performance not optimized. No aphakic toric
SCL available.
o Post trauma
 RGPS
 DxCL BC = avg K of the good eye.
 FP analysis
 Optimally improves corneal distortions
 SCL
 Easier to fit
 Considerations for aphakia
 Look for vascularization.
o With trauma, a vasoproliferative response can be
stimulated.
 Prosthetic lens for cosmesis
 Piggyback improves cosmesis and enhanced optics.
o Refractive surgery

Radial Keratotomy
 Considerations
o Number of incisions
o Length of incisions, depth
o Residual astigmatism
o Corneal topography
 RGPs
o Preferred lens choice
o Indicated for irregular astigmatism
o Topography useful
o Pre-surgical data useful
o Generally rx reverse geometry sphere
 Cornea is now oblate.
o Sphere
 Use pre-RK Ks or slight clearance centrally
(no bubbles)
 Align mid-peripherally
 Relatively steep PC system, but need
sufficient edge lift
 Larger OAD to aid in centration and
stability
 RGP Fitting
o Conventional tricurve lens
 Want central AC
 Larger OAD and OZ
 BC align with transition between a flat
central zone and steeper midperiphery
o Reverse Geometry Lens
 May improve corneal physiology
 Conventional/larger OAD and smaller OZ
 Increases centration and alignment
 Flatter BC
 Peripheral curve system steeper than BC
 Average central values for initial BC
 Average peripheral values for PC
 Modify fit by evaluating central and
peripheral FPs.
o Lenticular
 Larger OADs
 Tripod bearing pattern
 Ideal somewhat feathery
 SCL
o Fewer incisions (<8)
o Shorter length of incisions (do not go to the limbus)
o Residual astigmatism. MR vision needs to be
acceptable and stable.


o Silicone hydrogels
o Problem with vascularization, especially with torics
due to prism.
 Regular corneal topography.
o Watch for “Edge Fluting”
 If fit on flat cornea, the lens sicks and the
edge rides a bit. This is seen with thicker
materials. It looks scallop-like.
 Photorefractive Keratectomy
 Use axial (useable OZ) and tangential (pt by pt power, not
too useful) maps
 SCL
o Conventional
o Reverse geometry
 RGPs
o Conventional (AC)
o Aspheric
o Reverse geometry
o Considerations similar to post-PKP
 Laser Assisted In Situ Keratomileusis
 Same as post-PRK
 SCL
o Consider reverse geometry
 RGPs
o Sphere first choice
o Reverse geometry if indicated.
Strategy for reverse geometry lens design for the post-surgical plateau cornea.
o Diagnostic Lens Selection- using numerical topography data
 BC determination
 Average values over the OZ size
o (7.23+7.23+7.21+7.16+6.96+6.95+7.33)/7 =
7.15mm or 47.25D
 Secondary Curve
 Average values from OZ to 2-3 mm away
o (7.33+8.90+9.14)/3 = 8.46mm or 39.87D.
Patient education
o “you will not go blind form this condition”
 blindness equates to complete darkness
 adequate vision highly possible with specialty lenses
o These patients
 Are usually scared
 Have had multiple surgeries/procedures
 Blame themselves for electing surgery
 Seen may doctors (OMDs and ODs)

Have been told that there is nothing else that can be done or that
they will go blind.
o Do not promise results
Therapeutic CL


Reasons for Using
o Protection of the corneal surface, where the lens serves analgesic, barrier,
or structural support roles (“bandage” lens)
 Relief or reduction of pain associated with corneal epithelial
defects or abnormalities.
 Facilitation and maintenance of corneal epithelial healing.
 Hydration or dehydration of the cornea
 Protection of the cornea from mechanical abuses
 Sealing of small corneal wounds and perforations by splinting the
wound and thereby restoring the AC.
o Aid in drug delivery to the ocular tissues by serving as a reservoir or
soaking the CL in the meds
o Improvement of vision for irregular topography.
o Prosthesis for ocular disfigurement.
Bandage Lenses
o General Basic Fitting Principles
 OAD
 Usually large to completely cover the corneal epithelium
(14.5-16.0mm). this allows less movement.
 Smaller lenses used when perilimbal bulbar conjunctiva is
distorted, redundant, or irregular, such as a scarred fornix.
 Lens Thickness
 Usually minimal to promote oxygen delivery
 Thicker lenses are often used for post-surgical wound leaks
as “scaffolding” for healing. This is the bringing of 2 edges
of the wound together. It can also smooth the TL with an
irregular cornea.
 Power
 To minimize thickness, power is usually plano with
spectacles worn over the bandage lenses.
 If power is found to be necessary, consideration should be
given to overall lens thickness.
 Water Content
 Very controversial area
 Some believe that high water is better for dry eyes because
it acts as a fluid reservoir
 Others believe that low water is better for dry eyes due to
less dehydration effects.
 Lens Movement
 Should have less movement than that for cosmetic fits






Should not be too tight that they indent the sclera/vessels.
Minimization of lens movement is believed to facilitate
patient acceptance by decreasing lid sensation.
WT

DW preferable to avoid complications but sometimes not
possible.
 EW necessary when specified by the particular disease
entity.
Complications
 Edema and hypoxia
 Neo
 GPC
 Sterile infiltrates
 Ulcers
Examples
 Bausch and Lomb
o B4 Plano, Plano T, O4 Plano
 Ciba
o CSI Clarity FW
 CooperVision
o Permalens Therapeutic
 United CL
o UCL Bandage Lens
 these are all more expensive, so most use an off-label lens,
such as AV
Indications
o Traumatic Corneal Abrasions
 Traditional treatment: CAP
 Alternative treatment: CAP with NSAIDs
o Corneal Epithelial Abnormalities/ Persistent Epithelial Defects
 RCE
 Causes
o Mechanical trauma
o Corneal dystrophies: EBMD, Reis-Buckler, lattice,
granular, and macular.
 Symptoms: pain, photophobia, lacrimation, and
blepharospasm
 Use of a bandage CL
o Reason to fit
 Reduce acute FBS/ pain
 Dehydration
 Promote healing/ re-epithelialization
o What to fit
 High water content hydrogel
 Minimal movement to promote healing





EW necessary for 2-3mo.
TPAs
o Hypertonic drops BID-TID to decrease corneal
edema
o Hypertonic ung hs if necessary
o Broad spectrum antibiotic prophylactically.
o Cycloplegic agent
o Pain medication
o Lubricating drops QID
Persistent Epithelial Defects
 Numerous etiologies: bacterial, viral, fungal, chemical or
thermal burns, neuroparalytic keratitis.
o Ulcer/epithelial defects that wont heal.
 Herpes simplex
o One of the most common causes of PED
o Treated medically for a long period if time before
bandage lenses are tried.
o Use of a bandage CL
 Reason to fit
 Promotion of healing
 Drug reservoir for antivirlas
 Decreased discomfort
 What to fit
 High water lens worn EW until
healing has occurred
 TPAs
 Bandage lens with concomitant use
of an antiviral agent and
corticosteroids.
 Bandage lenses with decrease the
time of healing.
Meesman’s Juvenile Dystrophy/ Salzmann’s Nodular
Degeneration
 Reason to fit
o Relefi from pain, irritation, photophobia
o Improvement of vision
 What to fit
o Low water, thin lens
o DW schedule
o Regular cosmetic fitting standards
Mooren’s Ulcer
 Reason to fit
o Relief from pain
o Promote healing
 What to fit
o Low to medium water content lenses



TPAs
o Corticosteroids in conjunction with lens if necessary
Common/ Wet Filamentary Keratitis
 What is it? Secondary nonspecific diagnosis from primary
precipitating clinical conditions which disrupt corneal
integrity.
 Appearance: fine twisted threads of corneal epithelium
attach at their base to the surrounding epithelium.
 Symptoms: FBS and pain, blepharospasm, and epiphora.
 Treatment goal: remove the filaments
o Mechanical removal (1st)
o ATs and ung qhs with no preservatives; punctual
occlusion.
o Use ocular acetylcysteine, a mucolytic agent with
decreases the viscosity of mucus, making it easier to
peel off.
o Use of a bandage CL
 Reason to fit
 Mechanical protection
 Pain reduction
 Promotion of healing
 Stabilization of precorneal tear film
 Not to improve VA
 What to fit
 Low to medium water content lenses
 TPAs
 Wet condition often requires
bandage lens with concomitant use
of corticosteroid and atropine.
 May consider hypertonic gtts if
cornea is edematous.
 ATs and ung
Thygesons Superficial Keratitis
 Unknown etiology: viral etiology suspected
 Onset: 2nd and 3rd decade
 Appearance: oval or round grouped punctuate
intraepithelial deposits composed of numerous dotlike or
stellate opacities filled with filaments (15-20, but up to 50).
 Symptoms: FBS, burning, and tearing with popping at the
surface.
 Use of a bandage CL
o Reason to fit
 Relief from pain, photophobia, and FBS
 Promote epithelial healing
 Improvement of VA


SLK

o What to fit
 Low water, thin lens, DW schedule
TPAs
o Symptomatic relief through bandage lens with
concomitant use of low-dose corticosteroids and
lubricants.
Unkown etiology; frequently associated with
hyperthyroidism
 Chronic inflammation characterized by inflammation of the
superior tarsal and superior bulbar conjunctiva
 More prevalent in females
 Symptoms: burning, pain, photophobia, blepharospasm,
and FBS
 Use of a bandage CL
o Reason to fit
 Relief from pain, photophobia
o What to fit
 Low water, thin lens, DW schedule
 Large OAD (16mm) to protect the superior
cornea.
 TPAs
o 0.5% silver nitrate usually tried initially, but
condition returns.
o Pressure patching next to relieve initial discomfort,
than bandage lens.
o Chronic Edema
 Fuch’s endothelial dystrophy/ Bullous Keratopathy
 Most common cause of BK is cataract surgery
 Symptoms
o Severe pain
o Loss of vision
 Use of a bandage CL
o Reason to fit
 Dehydration- draw out edema
 Pain reduction- protect exposed nerves
 Promote healing
 Improve vision
 Temporary measure while waiting for
surgery
o What to fit
 Thick high water content hydrogel
 Adequate movement
 Fuch’s may be DW or EW
 BK almost always EW
 TPAs
o
o
o
o
Hypertonic gtts BID-QID
Hypertonic ung hs
Cycloplegic agent
Steroid (to decrease inflammation) and prophylactic
antibiotics.
o Mechanical Irritations
 Entropian and trichiasis
 Reason to fit
o Corneal protection
o Pain reduction
 What to fit
o Low water content hydrogels
o Durable polymers
o Frequent replacement program ideal
o DW preferable, but EW possible if there are
multiple lashes or if the entire lid is turned in
 TPAs
o None necessary but ung hs is beneficial for DW
patients.
o Possibly epilation
o Severe Drying and Erosive Conditions
 KCS/ Pemphigoid/ Sjogern Syndrome
 Ocular Pemphigoid
o A bilateral, chronically progressive disorder which
occurs in about 70% of people who suffer from
ciccatricial pemphigoid, a systemic autoimmune
disease which produces lesions of the skin and
mucous membranes.
o More common after age 60 and more common in
women.
o Ocular involvement is characterized by
 Progressive shrinkage of the conjunctiva due
to the production of fibrous tissue at the
level of the conjunctival basement
membrane
 Loss of goblet cells
 Ciccatrization of lacrimal gland ducts and
damage to the meibomian gland orifices.
 Symblepharon, keratoconjunctivitis sicca,
entropian, trichiasis, and eventually
keratizition of the conjunctiva and cornea.
Ankyloblepharon (fusion of the lid margins)
may also occur.
o Reason to fit
 Hydration
 Protect the cornea



Promote healing
Pain reduction
But, increased risk of CL related
complications.
o What to fit
 Thicker, larger diameter hydrogel lenses
with low water content
 Scleral lenses
o TPAs
 Aggressive preservative-free lubricating
therapy hourly
 Anti-staphylococcal therapy for blepharitis
may be combined with bandage lenses
 Immunosuppressive drugs and steroids.
Surgical Considerations
 Post-penetrating/ Lamellar Keratoplasty
o Reason to fit
 Mechanical protection from sutures
 Wound leaks
 Promote healing
 Visual enhancement
o What to fit
 Thicker, medium water content hydrogels for wound leaks
 For PED, high water content is better
 RGPs for visual enhancement (irregular astigmatism)
o TPAs
 May be combined with bandage lenses to enhance the therapeutic
effect.
 Post-PRK
o Reason to fit
 Relief from pain
 Promotion of healing
o What to fit
 Thin, high water content hydrogel
 Minimal movement
o TPAs
 Voltaren and/or steroids may be combined with lenses at surgeon’s
discretion.
 Post-RK
o Reason to fit
 Improve vision
o What to fit
 RGPs
Drug Delivery



Hydrogel CLs should improve drug contact time and thereby increase and
promote drug penetration into the cornea and anterior segment of the eye.
Drug absorption and release were therefore also found to be dependent to a
certain extent on the CL parameters.
o Depends on water content. High water absorbs more of the drug and
releases it faster.
Examples
o Pilo, CAIs, cystein HCl, acetylcystein, antibiotics, and corticosteroids.
Collagen Lenses
 What are they?
o Lenses made of procine or bovine collagen scleral strands.
o Available in 12, 24, or 72 hour dissolution rates
o Stored in a dry state
o Do not contain powder, OAD = 14.5-16mm, BC = 9.0mm, ct = 0.150.19mm, Dk/L = 27; acts like a 63% water content hydrogel
o Currently marketed for ocular surface protection following cataract and
refractive surgery, PK, and traumatic epithelial defects.
o Must be hydrated prior to application with drugs, saline, etc.
o Fragile
o Costly
o Cons: discomfort and reduced VA (20/100-200) due to it dissolving. It
dissolves fast and in chunks. Does not melt evenly.
 How are they applied?
o Lenses are presoaked for approximately 5-10 minutes.
 May be soaked with antibiotics, steroids, or saline.
o Anesthetic is applied.
o The lens is placed onto the cornea or lower cul-de-sac using forceps.
o The patient is asked to close their eyes and gentle pressure is applied.
 Indications for use
o Short term corneal protection
o Promote epithelial and stromal healing after surgery
o Lubrication
o Drug
Fitting those with Irregular Topography
 Topography is the starting point, but must rely on FP analysis. The goal is to
minimize areas of excessive clearance (bublles and staining) and harsh bearing.
 Monitor corneal stainging
o Swirl pattern indicates that the lens is rubbing on the K in a circular
motion.
o Dimple veiling means that there is too much AC
o 3-9 staining menas that there is too much edge lift.
 Goal: small area of bearing with central clearance. Border has feathery transition
between touch and clearance.
 Post-traumatic corneal scar
o Commonly associated with corneal lacerations or corfneoscleral
lacerations
o Topographical changes are dependent of the extent of the injury
o Effect on vision is dependent on residual scarring and topographical
changes.
o Modes of correction
 Spectacles
 Not as good (does not correct irregular astigmatism)
 CL
 SCL molds to eye, meaning that it is worthless
 Hybrid- SCL/HCL mix- expensive and breaks. decreased
O2 permeability.
 RGPs are the best.
Prosthetic CL
 Goals
o Improve cosmetic appearance of disfigured eyes
o Reduce glare and photophobia
o Eliminate diplopia
o Provide optical correction
o Provide occlusion in amblyopia therapy.
 Cornea
o Conditions for which prosthetic lenses can be used
 Leukoma, microcornea, band keratopathy, and bullous
keratopathy.
o Artificial iris and/or artificial pupil depending on whether it is a seeing eye
or non-seeing eye.
 Iris
o Conditions
 Heterochromia, aniridia, albinism, diplopia secondary to
iridectomy or polycoria, and coloboma
 Pupil
o Amblyopia therapy
o Leukocoria secondary to an inoperable cataract
o Photoconvulsive epilepsy treatment
Color Vision Deficiency
 Red-green color deficiency
 X-chrom lens/ Magenta/ Red lens
o Soft vs. rigid
 Ethics
Hybrid Contacts
Technology
 1977- Precision-Cosmet acquires rights to rigid-soft bonding technology
 1985- Saturn II is the first commercially marketed hybrid lens.
 1989- Sola-Barnes Hind purchases Saturn II technology and introduces new and
improved design- the SoftPerm lens.



2001- California-based research group begins developing a high-Dk hybrid lens.
The lenses to be developed have a higher Dk, are more durable, easier to fit, and
include a full continuum of indications.
2005- SynergEyes receives FDA approval for SynergEyes A and SynergEyes KC.
2006- SynergEyes receives FDA approval for SynergEyes PS and SynergEyes
Multifocal.
SynergEyes
www.synergeyes.com

Contact Lens Designs
o The RGP is great for optics, and the soft skirt also reduces movement,
keeping the lens centered.
o Material

Paragon HDS 100 GP Center (Dk 100) HydrolEyes Surface
 Paflufocon D

27% Water Non Ionic Skirt (Group I)
 Hemiberfilcon
 Patented Hyperbond Junction
o Engineered Design
 14.5mm OAD
 8.4mm rigid center
 7.8mm optic zone
 Skirt thickness consistent across full power range.
o Features and Benefits
 Gas permeable rigid center for optimal visual acuity. Maintains
spherical shape over normal and irregularly-shaped corneas.
 Precise optics centered over visual axis to correct haloes,
sensitivity to light, glare, and blurry vision.
 Soft skirt material is dimensionally stable and expansion-free for
increased stability for consistent, predictable vision.
o Trial Lens
 Marked with a laser

o Types
i.e. A7992
o A = A lens
o 79 = 7.9 BC
o 92 = 9.2 skirt

SynergEyes A
o Patient Candidates
 Naturally occurring ametropias
 Moderate to high myopes, hyperopes, and astigmats who
desire the pristine vision of an RGP with the all day
comfort and stability of a soft lens.
o Up to 6D of cyl can be corrected.
 Any patient who has never achieved good vision with
soft/soft toric lenses or who cannot tolerate the comfort of
RGPs.
 Current GP wearers
 Teens and athletes
 CL dropouts
 Irregular Astigmatism
 Mild keratoconus or mildly oblate corneas.
o Trial Kit
 20 lenses: 10 BC- 7.1-8.0, 2 skirts each
 Can be used for multifocal fittings
o Available Parameters
BC
SC
Sphere Power
7.10-8.00 in 0.1mm steps
1.0mm, 1.3mm flatter than the BC
+8.00 to -8.00 in 0.25D steps
+8.50 to +20.00 in 0.50D steps
-8.50 to -20.00 in 0.50D steps
o Prescribing
 Empirical
 Calculator, available on the SynergEyes website
 Consulting

Done via calling the consultation department (877-7332012) with the following information
o Patient name or number
o Keratometry
o Manifest refraction
o HVID
 This measurement can be obtained by
utilizing various topographes. If this is not
possible, a statistically based default value
will be used.
o Fitting Philosophy for Normal Corneas
 Choose the BC
 Never prescribe flatter than or “on” flat K. Prescribe lenses
at least 0.3mm (1.5D) steeper than flat K.
 Changes in the BC radius will affect the resultant
correction power of the lens while on the eye. Therefore,
the power of the lens may require proportionate adjustment.
Each 0.1mm of BC change requires 0.5D power
adjustment.
o This should follow the SAM/FAP rule.
 Ex. 7.6 -3.00 → 7.5 -3.50.
 Skirt curves 1.0mm flatter are recommended for low
eccentricity values. The 1.3mm flatter skirt is
recommended for high eccentricity values.
 HVID changes the sagittal depth on two patients with the
same Ks. An increased HVID means an increased sagittal
depth, therefore a steeper skirt is required, or a steeper BC.
 Evaluation of fluorescein
 High molecular fluorescein is optional for the initial fitting
for normal corneas.
o It is best to purchase the Fluorescein from Wilson
Fluoresoft 0.35% ampules or Flurasafe.
 Place 1-2 drops high molecular fluorescein in the bowl of
lens with saline before application. To apply the lens, have
the patient look down into the lens and bring the lens up to
contact the cornea.
 Inform the patient that the fluorescein might sting. Assure
the patient that they will not feel that with their final lenses,
but it is necessary to evaluate the fit.
 Allow the excess fluorescein to dissipate and observe the
fluorescein pattern after 30 seconds of normal blinking.
Subtleties of the fluorescein pattern become more apparent
with time.
 Upon evaluation, there should be some apical vault.
o Apical Clearance is the desirable pattern. Apical
bearing may result in late-onset tightening.
o Insufficient Apical Clearance
o Excessive Apical Clearance



The use of a Wratten filter may be helpful in viewing
fluorescein patterns.
Evaluation of movement
 Look at the edge of the soft skirt where it meets the sclera.
There should be no compression of vessels on the sclera,
and the lens should move with little pressure from the
lower lid with a “push up” test. There should also be no
“edge fluting.”
 Observe centration and movement in primary gaze. The
lens should exhibit slight movement (0.25mm) with a
normal blink. There should be a slight lag on up-gaze.
 Let stand for 30-45 min. The hybrid family of lenses has a
tendency to tighten with increased wear time. If this lens is
not fit steep, adherence is a definite problem that can lead
to corneal edema and reduced wear time.
Over-refraction
 Spherical



With cyl >2.0D, try enhanced profile or go a little steeper.
If there is any unusual residual astigmatism, perform a K
reading over the center of the rigid lens.
 If over-refract is greater than 4.00D, adjust for vertex
distance.
Troubleshooting
 Tight fitting lens → Steepen BC
 Heavy bearing at junction → Steepen SC
 Insufficient apical clearance
o Steepen BC by 0.1mm (Ex. 7.7 → 7.6mm)
 Excessive apical clearance
o Flatten BC by 0.1mm (Ex. 7.6 → 7.7mm)
 Edge fluting




o This is due to the skirt being too flat, so steepen the
skirt curve radius
 Ex. 8.9 → 8.6
 If already steep, go to a steeper BC.
Scleral Impingment
o Switch to flatter skirt curve radius
No movement upon blink with insufficient apical clearance
o Steepen BC by 0.1mm
No movement upon blink with adequate apical clearance
o Steepen skirt curve radius
Tight lens seal-off
o This is observed as a dark heavy touch ring of
bearing at junction
o Steepen the SCR

Ex. Change SCR from 8.5 to 8.2mm
o If already in the steep SCR, move to the next
steeper BC/SCR combination.
o Fitting Philosophy for Irregular Corneas




Choose an appropriate SynergEyes lens design based on the
corneal shape, not on the patient history or diagnosis.
 If uncertain of which design is most appropriate, begin with
SynergEyes A. Many kertoconic or post-surgical eyes that
are mildly prolate or oblate, respectively, can be fit with the
SynergEyes A design. Have patients earn the complexity of
the advanced designs.
Empirical fitting using the SynergEyes A lens calculator or fitting
0.3mm steeper than flat K is NOT RECOMMENDED for irregular
corneas. Only rely on fluorescein. The diagnostic set is essential to
evaluate proper fit. The use of high molecular weight fluorescein is
absolutely necessary.
Select the initial diagnostic lens close to steep K. Attempt to vault
over the irregular areas. Central clearance (or a “feather touch) is
the goal. Touch between the back surface of the lens and front
surface of the cornea should be minimized.
Fluorescein pooling without bubbles is an acceptable fit.
 Persistent central bubble → switch to SynergEyes PS.


 Bubbles and touch → switch to SynergEyes KC
PMD
 With PMD patients, start with SynergEyes A. If apical
clearance is not achievable and if the touch is within the
central 6mm of the lens, switch to SynergEyes KC. If touch
is peripheral and within the RGP center of the lens. Switch
to SynergEyes PS.
SynergEyes KC
o Introduction
 This is the first hybrid contact lens with FDA clearance,
specifically designed for patients with keratoconus, post-LASIK
ectasia and high eccentricity.
 It offers centration, comfort, and stable optics on a range of
emerging, moderate, and globus cones. Because it is aspheric, a
steeper BC is sometimes required. No orientational positioning in
eyes with off-centered bulging/thinning is required.
o Patient Candidates
 Ideal for central or symmetrical keratoconus.

The problem comes with highly prolate corneas and touch.
o This fluorescein pattern is contraindicated for
SynergEyes KC.
Emerging to moderate peripheral cones
Emerging to advanced central cones
Oval, nipple, and globus cones



o Trials
 24 lenses: 8 BC- 5.70-7.10, 3 skirts each.
 Powers range from -4.00D to -14.00D sphere power depending on
the BC selection.
o Available Parameters
Diameter
BC
SC
Sphere Power
14.5mm
5.70 to 7.10 in 0.2mm steps
Steep, medium, flat
Plano to -20.00 in 0.50D steps
o Fitting Guide
 Finding the Cone
 The radius of the apex of the cone can be determined by
moving the cursor in the Corneal Topography program
screen directly over the center of the hottest spot on the
cornea.
 If Corneal Topography is unavailable, an estimate of the
radius of an inferior cone can be determined by
keratometry with the eye in upward gaze.
 Determine the initial diagnostic lens BC by selecting the closest
BC radius in relation to the keratoconus apex radius (Steep K).
 Ex. Keratoconus apex = 52.50D
o Round to next steeper BC = 6.30 (53.50D)
 In the absence of topography, use steep K to determine the
initial diagnostic lens BC.
 Start with the determined BC in the medium skirt curve option.
 Follow the fluorescin instillation instructions as directed with the
SynergEyes A.
 When ideal fluorescein pattern is achieved, over-refract to
determine the final lens power as instructed in the SynergEyes A
section.
o Ideal SynergEyes KC Fit
 Optimum fit will demonstrate apical clearance over the central
cornea/ corneal apex, with the steepest BC that is free of central air
bubbles with greater than 2mm diameter. Smaller bubbles will
typically dissipate. There should be little or no touch in rigid
portion of lens. Landing occurs in the soft skirt.
 Paracentral alignment under soft skirt.
 Soft skirt free of scleral impingement and “edge fluting”
 Lens free to move on lid push-up
o Additional Fitting Tips
 The steeper skirt curve radius will add sagittal depth to the lens,
and lift the bearing point to produce a lighter landing
 This improves the comfort and prevents late onset
tightening
 Many corneas with emerging or moderate keratoconus may be fit
with the SynergEyes A lens design. SynergEyes KC is required
with significant ectasia and high eccentricity.
o Troubleshooting
 If bubbles are present, remove the lens and re-insert with solution
in the bowl of the lens. Identify the shape and location of bubbles.
 If large central bubble is present, flatten the BC radius.

If significant touch is observed, note the location of the touch area.
 If the area of touch is observed at the steepest area of the
cornea, steepen the BC radius.


SynergEyes PS
If significant touch is observed peripherally at the rigid/soft
junction, steepen the skirt curve radius.
o Introduction
 First FDA-cleared hybrid contact lens specifically designed with
reverse geometry for patients with oblate corneas resulting from
refractive surgery, corneal trauma, or degenerative conditions,
including penetrating keratoplasty and/or Intacts for keratoconus
 Offers centration, stability, comfort, and a high degree of visual
success, even in most difficult cases.
 Reverse curve design specifically addresses the altered corneal
shape resulting from refractive surgery.
 This already has an enhanced profile.
 Design over 3 reverse curve options for customized fitting on a
variety of oblate corneas.
o Advanced Lens Design
 Oblate posterior surface
 6.5mm spherical posterior OZ
 8BC offered, 7.6-9.0 in 0.2mm steps
 Secondary curve, “Lift” (steeper than BC) extends across skirt
junction to 9.0mm
 Adjusting the lift allows fine tuning of the lens design to
optimize fit.
o Available Parameters
BC
SC
Lift
Sphere Power
o Patient Candidates
7.60 to 9.00 in 0.2mm steps
8.3mm or 8.6mm
L1 (flat), L2 (medium), L3 (steep)
+2.00 to -6.00 in 0.25 steps






Post-refractive surgery/ post-LASIK patients
Post-RK
Post-PRK
PMD
Degenerative corneal conditions or corneal trauma
Post-PK and/or Intacts for keratoconus
o Fit

Select the initial BC
 Find the mean K of the central 6mm of the cornea.
 Using the SynergEyes PS Diagnostic set, select the nearest
BC steeper than mean K.
o E. 36.75/40.75 x035 = 38.75D = 8.71mm
o Round to the next steeper BC = 8.6mm.
 Select the initial lift
 Begin with the selected BC in Lift “L2” (medium)
 Apply lens and evaluate the fluorescein pattern as with the
SynergEyes A lens.
 With a successful fit, over-refract to determine the lens power.
 All diagnostic lenses are plano power.
o Ideal SynergEyes PS Fit
 Apical clearance over central cornea. Optimum fit has little or no
touch in the rigid zone of lens- total corneal clearance.
 Clearance free of bubbles over flattest corneal zone.
 Light touch at 9mm chord diameter
 Alignment under soft skirt
 Soft skirt free of scleral impingement or fluting
 Lens free to move on lid push-up.
o Fluorescein Pattern
 Insufficient Lift

Appropriate Lift
o Tips for Achieving Success
 If bubbles are present, identify the shape and location.
 If the bubbles are round and located centrally, it is
generally due to excessive lift. Flatten the BC.


If the bubbles are arc-shaped and located neat the skirt
junction, or if bubbles are seen both peripherally and
centrally, decrease the lift.
If excess touch is observed, note the location of touch area.
 If touch is central, steepen the BC.

If the area of touch is more peripheral, increase the lift.
o Additional Fitting Tips
 Changing the overall sagittal depth of the lens by changing either
the BC or the lift allows for maximal customizing of the lens fit.
 Air bubbles beneath the RGP portion usually indicates a
need for less sagittal depth.
 Areas of excessive touch within the RGP portion indicates
a need for greater sagittal depth.
 If the 8.6mm skirt curve exhibits edge fluting, order the 8.3mm
skirt curve.
 More highly oblate corneas, those with the greatest difference
between the central Ks and the peripheral corneal curvature, are
more likely to need the steeper Lift (L3).
 Mildly oblate corneas will likely benefit from the flatter lift (L1),
or may even be fit with the SynergEyes A lens design.
 Post-surgical corneas with ectasia may experience better results
with the SynergEyes A or KC designs, depending on the location
and amount of ectasia.

SynergEyes M
o Near center annular bifocal design.
o Available Parameters
BC
SC
7.10 to 8.00 in 0.1mm steps
1.0 (steep), 1.3 (flat)
Sphere Power
Add Power
Add Segment Size
+4.00D to -8.00D in 0.25 steps
-8.50 to -9.00 in 0.50D steps
+1.25, +1.75, +2.25
1.9mm, 2.2mm
o Target Patients
 RGP MF/BF CL wearers
 Soft MF CL Wearers
 SV CL Wearers/ MV Patients
 Patients who wear BF or Progressive Spectacles
 Emerging Presbyopes
o Fit
 Enter the patient’s flat K values into the window to the left of the
SynergEyes Multifocal Slide Rule. The center window will display
the appropriate BC and the right window will display the
appropriate skirt curve.
 Turn the slide rule to the reverse side, and with Rx in minus cyl
form, enter the patient’s sphere power into the window to the left.
Order the lens power that appears in the right window.
 Determine the patient’s dominant eye, or eye preference for
distance and near vision, and then choose segment size.
 For most patients, select the 1.9 segment for the
dominant/distance eye and the 2.2 segments for the nondominant/ near eye.
 Patients with small pupils or greater demand for distance
vision may prefer the 1.9 segments OU while patients with
large pupils or a greater demand for near vision may prefer
the 2.2 segments OU
 Determine the patient’s add power by using the chart below
Age
<50
50-57
>57

Dominant
Eye Add
+1.25
+1.75
+1.75
Non-Dominant
Eye Add
+1.25
+1.75
+2.25
Optional
 If you have a 20 lens set of trial lenses, insert the
recommended lenses from the slide rule into tha patient’s
eyes.
o Over-refract for distance vision.
o Use a trial frame with distance over-refraction to
demonstrate distance in normal light.
o Use hand-helds in either pl, -0.50D or +0.50D to
demonstrate near vision.
o Adjust parameters if necessary before ordering.

o Tips





o Note


Order lenses
It is important for patients to wear the SynergEyes MF lenses for
1-2 weeks to adapt to the new optical system and experience the
lenses in their everyday environment.
If patient is experiencing unacceptable distance vision
 Over-refract monocularly with handheld trial lenses and
adjust the distance Rx accordingly.
 Confirm the add power with new distance Rx and reestablish patient’s preferred near focal range. If overrefraction fails to provide acceptable distance vision,
o Perform sphero-cylinder over-refraction.
o If cylinder is present in over-refraction, perform
keratometry or topography over the lens.
o If on-eye flexure is observed by over-keratometry
or over-topography, order enhanced profile design.
If you have confirmed the distance prescription, and you do not
observe on-eye flexure, then consider decreasing the segment size
on the non-dominant eye from 2.2mm to 1.9mm seg.
If the patient is experiencing unacceptable near vision within
preferred working distance:
 Evaluate and determine patient’s near focal range with
dispensed lenses.
 Confirm appropriate distance vision prescription.
 Re-check near vision with any additional distance
prescription adjustment.
 Use handheld lenses to achieve preferred near vision range
and re-calculate patient’s ideal distance and near Rx. Reorder lenses with new parameters.
If near vision is unachievable at any distance:
 Confirm lens centration over pupil. If decentered, consider
steeper BC to improve centration.
 If well centered, consider increasing segment size on the
dominant eye.
Slight ghosting or reports of “3D” vision upon dispensing are
typical effects of a functioning simultaneous vision system. After
an adaptive period (typically 1-2 weeks of 8-10 hours of wear), this
effect will usually resolve. Patients unable to adapt after 2 weeks
may not be ideal candidates for simultaneous vision.
Lens Insertion
o Always wash and dry your hands using mild lanolin-free soap and a lintfree towel before handling the lenses.
o To reduce the risk of switching your lenses, practice handling your lenses
in the same order, i.e., always start with your right lens.
o To begin, remove the SynergEyes contact lens from the case using the pad
of your finger.
o Rinse the lens with Optifree Express and inspect the lens for debris or
nicks.
o With the lens seated bowl-side up on the end of your index finger, pull
down the lower lid with your middle finger.
o With the other hand, reach over and hold the upper lid by placing the
fingers at the bottom of the lashes.
o While looking straight ahead in a mirror, place the lens gently on the
center of the eye.
o Rinse your contact lens case with tap water and air dry.

Lens Removal
o Make sure your fingers are clean and dry.
o Pull down the lower lid of your eye with your middle finger.
o Look straight ahead in a mirror or with your head tilted slightly forward
o Keep the pads of the thumb and index finger together.
o Grasp the lens at the 6 o’clock position.
o Allow air underneath the edge and lift the lens away from the eye straight
out.

Caring for your SynergEyes lenses
o 6-month replacement. Lenses are provided in 2-packs.
o Solutions
o Each day after you remove your lenses, you must digitally clean them
prior to overnight storage for disinfection.
o Put the lens bowl-side up in the palm of your hand, apply a few drops of
Alcon’s Opti-Free Express solution and rub the rigid portion of the lens in
a circular motion with the pad of your finger. Be sure to thoroughly
digitally clean the entire lens and rinse well. Ignore the “no rub”
instructions on some packages.
o Rinse the lens while still in the palm of your hand with a steady stream of
solution. This keeps the lens clean, clear and comfortable to wear.
o Fill your lens case with Opti-Free Express fresh solution and place the lens
in the well with the bowl-side up. Never “top-off” or use old solution.
Supplemental use of a soft lens daily cleaner or enzyme cleaner may be
beneficial.
o If using Clear Care, you must use the specifically provided case with the
neutralizing disc and soak the lenses a minimum of 6 hours before
inserting again.
 Optisept/Ultracare is also OK. This is actually a little better since
there is complete neutralization of the peroxide and there is a new
tablet with each use that is coated with HPMC for increased
comfort.
o SynergEyes contact lenses should be replaced every 6 months. Contact
lens cases should be replaced every 3 months.
o Opti-Free Replenish is OK for diagnostic lenses, but not for daily use.
o Upon follow-up examination, remove the lens and examine the cornea.

Case Examples
o