contact
lens case reports
Corneal Changes after Everted Hydrogel Lens
Wear
BY
PATRICK J. CAROLINE, FAAO, & MARK P. ANDRé, FAAO
In our June 2005 column "Topographical Changes
after Everted Silicone Hydrogel Wear," we demonstrated the incredible changes associated
with wearing a high-minus silicone hydrogel lens inside-out.
Recently, one of our established patients returned to our clinic with vague symptoms
of blurred vision with his left eye only. He was a high myope whom we had fit with
–13.00D CSI-T (CIBA Vision) soft lenses approximately 10 years ago. Historically,
the patient had done extremely well with his lenses, enjoying 20/25 vision OU and
comfortable, all-day lens wear.
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Figure
1. Slit lamp photography of the patient's eyes following lens removal and the instillation
of fluorescein. Note the corneal imprint OS.
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Telltale Topography
At this visit, the patient's visual acuities were OD 20/25, OS
20/25. Slit lamp examination showed both lenses to move and center well with the
blink. There appeared little difference in the position and overall dynamics of
the two lenses. The patient did exhibit some mild peripheral neovascularization
OU, but it hasn't progressed in recent years.
We
removed the lenses and instilled fluorescein. The surface of the right cornea was
clear and free of any staining. The left eye, however, revealed a corneal imprint
created by inadvertently wearing the high minus soft lens inside-out (Figure 1).
Corneal mapping of both eyes showed a slight ring pattern beginning to develop on
the surface of the left eye (Figure 2). This case demonstrates how some soft contact
lenses can be worn inside out without a significant compromise in vision or patient
comfort.
Don't Judge by Comfort
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Figure
2. Corneal mapping OU post lens removal. |
In a recent unpublished study at Pacific University, we asked
12 non-adapted lens wearers to participate in a masked study in which we applied
a –10.00D silicone hydrogel lens right-side-in on one eye and inside-out on
the other. The subjects rated lens comfort on a 0 to 10 scale with 0 representing
poor comfort and 10 excellent comfort. Five minutes after lens application, the
subjects rated the right-side-in lens at 8.5 and the inside-out lens at 7.2.
We then instructed the subjects to sleep with the lenses over
night. The subjects again rated lens comfort immediately upon awakening, and this
time they rated the right-side-in lens at 6.5 and the inside-out lens at 6.3. This
study shows that patients can successfully wear some soft lenses inside-out and
experience only vague symptoms of ocular discomfort, most likely related to the
corneal topography changes.
The take-away lesson from this case is that if you see a corneal
imprint similar to what's in Figure 1, it most likely represents a lens worn inside-out.
Patrick Caroline is an associate
professor of optometry at Pacific University and is an assistant professor of ophthalmology
at the Oregon Health Sciences University. He is also a consultant to Paragon Vision
Sciences and SynergEyes, Inc. Mark André is director of contact lens services
at the Oregon Health Sciences University and serves as an assistant professor of
optometry at Pacific University. He is also a consultant for Alcon Labs, CooperVision
and SynergEyes, Inc.
Contact Lens Spectrum, Issue: May 2006