The anticipated approval and arrival of latheable soft silicone hydrogel contact lenses may give optometrists who treat keratoconus patients another option-for some patients, perhaps the best option ever, according to one expert.
Keratoconus has long provided an opportunity for optometrists to provide a remarkable service, Prof. Caroline said.
"It's wonderful to take a person who is virtually blind with traditional spectacle lens correction, and within seconds, after resting the contact lens on the eye, they can see 20/25 or 20/20," he said. "It's remarkable and, for me, there are few things in clinical practice more rewarding."
Prof. Caroline added that only about 10% of patients who carry the diagnosis of keratoconus go on to require a corneal transplant. That translates into 90% of these patients going through their entire lives with CL correction. That's an opportunity and yet a significant responsibility for all eye-care practitioners.
Fortunately, with the advent of advanced spherical, aspheric, and scleral lenses, optometrists have many rigid lens tools with which to provide both comfort and vision.
While Prof. Caroline said the vast majority-about 90%-of keratoconus patients do well with rigid gas-permeable CLs, some patients experience decreased wearing time and comfort, and today, for those patients, piggyback lenses or custom HEMA soft contact lens designs might be the ideal modality.
"On the very near horizon we're going to see the introduction of some new silicone hydrogel materials that can be lathe cut into custom keratoconus designs," he said. "We anticipate FDA approval for these latheable silicone hydrogel lenses in the very near future. With the introduction of these materials, we'll see a dramatic increase in the number of soft lenses being used for keratoconus."
Five fitting hints
In anticipation of optometrists seeing more patients who wish to convert from rigid lenses to soft silicone hydrogels, Prof. Caroline offered five simple soft CL fitting tips for keratoconus patients:
"When we put patients into a custom soft lens there's a lot of fluctuations in vision that take place during that first month of soft lens wear; so to maintain them and keep them seeing, we'll have them stay in their rigid lens in one eye while we slowly get all the powers adjusted with the soft lens on their other eye."
"Many patients, in fact, elect to put the cylinder into glasses over the top of the soft lens. That's especially advantageous for individuals who need a bifocal correction anyway, so we can incorporate that bifocal correction with the astigmatism correction," he said.
"Use peroxide solutions with caution, and listen to the patient," he said. "If a patient is putting in the lenses in the morning and having some burning and stinging, that's probably being caused by residual peroxide that hasn't been neutralized."
A thorough rinse with a preservative saline, prior to lens insertion, can easily be added to the regimen.
In closing, Prof. Caroline suggested referring keratoconus patents to an eye-care professional who specializes in CLs for the disorder.
"One thing optometry does poorly, which ophthalmology has embraced, is referring to colleagues who are trained and specialize in specific conditions or disorders," he said.
"Often, the best way to help a keratoconus patient is to put him or her in the hands of someone who has the tools and expertise in contemporary keratoconus fitting.
"Since only about one in 2,000 individuals carries the diagnosis of keratoconus, it may be in everyone's best interest to refer the patient to an experienced colleague," Prof. Caroline concluded.
Patrick J. Caroline
Prof. Caroline is a consultant for Paragon Vision Services, Mesa, AZ.