contact lens case reports
Fitting Stock Prosthetic Lenses
BY PATRICK J. CAROLINE, FAAO, & MARK P. ANDRÉ, FAAO
Prosthetic soft contact lenses cosmetically mask anomalies that involve the cornea, iris or crystalline lens. Additionally, they effectively modulate the amount of light entering the eye and can benefit patients in selected cases of anirida, photophobia, lens subluxation, iris coloboma, surgical or laser iridectomy, polycoria, microcornea, heterochromia and band or bullous keratopathy.
Today, prosthetic soft lenses are available in a wide range of materials and designs in either stock (CooperVision and CIBA Vision) or custom soft lens parameters from a number of laboratories around the world.
In some cases, stock prosthetic soft contact lenses offer distinct advantages over their custom counterparts. These include computer-generated iris patterns for adequate color matching and excellent color reproducibility, stock contact lens parameters with 48- to 72-hour lens delivery and diverse diagnostic fitting sets to facilitate appropriate color matching.
Figure 1. Cosmetic appearance post trauma.
|Figure 2. Cosmetic appearance with the stock prosthetic soft.|
Stock Lens Fitting
Patient JR is a 22-year-old male who suffered a blunt trauma injury to his left eye in May 2001. Upon initial presentation, his visual acuities were OD 20/20 and OS NLP (Figure 1). Since the injury, the left eye has undergone continual medical therapy for post trauma glaucoma and bullous keratopathy.
In November 2002, the patient was referred to our practice for cosmetic management of his blind left eye. We subsequently fit the patient with a Cooper stock prosthetic soft lens with an 8.7mm base curve, 4.5mm black pupil, 14.5mm diameter and a color that best matched his sighted right eye (Figure 2).
A common cosmetic complication with the stock prosthetic lenses stems from the standard 12.0mm iris pattern. This diameter is frequently too large relative to the "normal eye." To manage this size discrepancy, we often fit a matching cosmetic lens (with a clear pupil) to the sighted eye.
Cooper stock prosthetic lenses are available in nine colors, in a single base curve of 8.7mm and 14.5mm diameter. You can order the posterior surface with either clear or black backing. A stock 4.5mm pupil is available in both a clear center for sighted eyes or black center for blind or photophobic eyes.
CooperVision also provides custom prosthetic lens parameters that include expanded base curve radii of 8.4mm, 8.7mm and 9.0mm as well as expanded pupil diameters of 3.5mm to 5.0mm in 0.5mm increments. Custom spherical powers are available from -20.00D to +20.00D in the 4.5mm pupil diameter design.
Always keep in mind that stock prosthetic soft contact lenses are just one additional tool that you can use in the cosmetic or therapeutic management of patients following injury, surgery or corneal disease. You may require other prosthetic devices, such as painted scleral shells, cosmetic hard contact lenses, piggyback lenses and of course, custom prosthetic soft contact lenses.
Patrick Caroline is an associate professor of optometry at Pacific University and an assistant professor of ophthalmology at the Oregon Health Sciences University.
Mark André is director of contact lens services at the Oregon Health Sciences University and an adjunct professor of optometry at Pacific University.