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Opaque Lens Fitting for a Traumatic Iris
Coloboma
BY
MONICA L. GARDINER, OD, & MICHAEL R. SPINELL, OD, FAAO
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Figure 1. Traumatic iris coloboma extending
from 7 o'clock to 8 o'clock.
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Using special soft cosmetic lenses for prosthetic
purposes is well established and usually involves fitting a semi-stock, custom-printed
or hand- painted lens on the involved eye. This can become especially
challenging if a patient's irides are light in color because iris architecture and
color are so obvious in such patients.
We will describe the fitting of two different types of opaque
lenses to achieve the desired binocular cosmetic and visual effect for a light-eyed
patient who had a monocular iris coloboma.
History
Patient PG, a 52-year-old white male educator, presented with
an unusual history. At age 9 he accidentally pierced his left eye with a screw driver,
necessitating emergency surgery. The results of this surgery left him with surprisingly
good vision (20/25+) but a rather noticeable iris coloboma extending from 7 o'clock
to 8 o'clock (Figure 1), which caused almost constant photophobia, photopsia and
distorted vision.
Despite this apparent handicap, PG was still able to play in collegiate
and professional football and even sparked the interest of professional baseball
organizations. He had a relatively low refractive error (OD plano –1.50 x96,
OS plano –1.25 x046, OU +2.00D add). He wore eyeglasses mainly for near work
because he had difficulty adjusting to any type of bifocal or progressive lens.
We therefore placed our emphasis on solving his problem with light scatter and with
matching his iris color.
Initial Attempts
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Figure 2. The initial lens eliminated the photophobia,
but didn't provide a suitable color match with the unaffected eye. |
We first fit several semi-stock prosthetic lens designs. The first
was a prosthetic lens from CooperVision. These lenses come in several shades of
colors either with or without a black backing. They're also available with either
a clear pupil (4.5mm) or with a black or closed pupil that can range from 3.5mm
to 5.0mm in 0.5mm steps.
The first diagnostic CooperVision prosthetic lens was a #13 blue
lens without the black backing and with a clear pupil. Though the lens didn't match
the color of the good eye (Figure 2), it did position perfectly, move adequately
and more importantly, it immediately resolved the photophobia. We fit several other
similar lenses in different colors with only slight improvement in cosmesis.
The
second type of lens we fit was from the CIBA Prosthetic Lens set (CIBA Vision).
This slightly darker opaque contact lens was also not an optimal color match. We
fit several other similar opaque contact lenses with similar results.
Mix and Match
Our next approach was somewhat novel because it involved the use
of an opaque blue FreshLook ColorBlends lens (CIBA) that we piggybacked onto a special
Durasoft underprint lens (CIBA). Underprint lenses provide a definite opaque backdrop
and so are useful in trying to hide underlying colobomas and scars. They're also
available in either a light underprint or a dark (black) underprint design. If this
combination provides adequate cosmesis, you can then order a single lens that combines
the characteristics of both lenses.
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Figure
3. The final prosthetic lens on the afflicted left eye.
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We
placed this diagnostic lens using a light underprint on PG's eye. The lens centered
well, moved properly, eliminated the photopsia and provided a very close color match.
Figure 3 shows the final lens on PG's eye.
Because this lens is also available in a disposable version without
any type of underprint, we tried a plano FreshLook ColorBlends lens in opaque blue
on PG's good right eye. This new combination of lenses (Figure 4) provided excellent
optical and cosmetic results. The final lens we ordered for the afflicted eye was
a FreshLook ColorBlends opaque lens with a light underprint, 3.7mm standard clear
pupil, 8.6mm base curve, 14.5mm diameter and plano power. We ordered a supply of
standard FreshLook ColorBlends opaque blue lenses for the right eye.
We dispensed these lenses and scheduled the patient to come back
in one week for a progress evaluation. This appointment was important for assessing
both the physiological fit of the lenses as well as to assess any psychological
problems that might arise.
Conclusion
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Figure 4. The combination of the two lenses
provided an excellent binocular cosmetic effect and eliminated the photophobia. |
Fitting special prosthetic lenses can be challenging, especially
if light irides are involved. You must be aware of what specific options are available,
you must be flexible in trying different approaches and you must make sure that
the patient you're fitting has realistic goals.
In this particular example, we achieved excellent visual and cosmetic
results for a patient who had experienced photophobia and photopsia for more than
40 years through the use of a combination of a semi-custom lens on the afflicted
eye and a standard disposable opaque lens on the uninvolved eye.
Dr. Gardiner is a 2006 graduate
of the Pennsylvania College of Optometry. She is a graduate of East Carolina University
where she received a Bachelor of Science degree in exercise physiology. Dr. Spinell
is a graduate of the Pennsylvania College of Optometry where he is now an associate
professor. He is a Diplomate in the Cornea and Contact Lens Section of the American
Academy of Optometry and has authored many articles and chapters on contact lenses
and sports vision.
Contact Lens Spectrum, Issue: August 2006