When to Suggest Surgery for Keratoconus Patients
BY BEZALEL SCHENDOWICH, OD, FIACLE
Depending upon locale, contact lens availability, patient sensitivity and other factors, about 10 percent to 15 percent of lens-wearing keratoconic patients eventually require penetrating keratoplasty (PKP). When do we raise the question of surgery? What are the signs and symptoms of pre-surgical keratoconus?
Re-educate and Refit
Three years ago, we fit an early keratoconus patient with his first pair of contact lenses. He didn't return for his follow-up visits.
He came in three months ago complaining that his contact lenses had become unwearable. We found that his disease had progressed and so advised him to return for a refitting session. He instead requested a surgery referral.
Examination showed his corneas to be clear of scars, folds in Descemet's membrane or remarkable thinning. While his corneal curvatures had steepened over the intervening period, his keratoconus wasn't so advanced as to require surgery.
As a first step, we decided to educate this patient. We discuss-ed PKP with him; we described the technique, possible sequelae and aftercare. Most importantly, we reassured him that with well-fitting contact lenses he probably had years before he'd need PKP.
We work to keep our patients in well-fitting, non-abrading contact lenses for as long as possible for the following reasons:
- A pre-surgical cornea is far more structurally stable than a post-surgical cornea, especially after stitches come out
- Possible graft rejection
- Patients must take medication for prolonged periods after the graft
We also advise potential PKP candidates to carefully choose a surgeon and facility location so that they can present for examination expeditiously in the event of a suspicion of rejection.
Timing the Surgery
Even patients who have severely progressive keratoconus can successfully wear contact lenses. But for patients whose corneas are thin and scarred, obviously exhi-biting advanced keratoconus, it's critical to plan ahead for surgery.
Another of our patients wears both of his lenses daily for long hours. We advised him some time ago to have an introductory consultation with our corneal surgeon.
In our locale, patients face about a six-month waiting period once they get on the PKP list. After surgery they wait an additional six to nine months before a surgeon examines the eye to possibly remove stitches to reduce surgically induced astigmatism or to prescribe glasses. Considering this, patients could conceivably have an operated eye that is hardly useable and an advanced second eye that can no longer tolerate a contact lens.
When Surgery Isn't Possible
One of our happiest contact lens successes was in fitting a young woman who had severe bilateral ectasia with accompanying scarring. She can't undergo PKP because of other health problems and the effects of the medications involved in their care.
Although she's currently a successful lens wearer, we hope that medicine will eventually find a way to modify her physical condition to permit her surgery.
Making the Final Decision
The final decision to undergo PKP rests with the patient. He relies on our talents to keep him in well-fitting lenses as long as they're visually useful. Advising about the pros and cons of surgery and making a timely suggestion for surgery are among our most important responsibilities to these patients.
Dr. Schendowich is a preceptor in the Optometry Clinic at the Hadassah Academic College in Jerusalem, Israel and an adjunct assistant clinical professor of Optometry at SUNY Optometry in the Optometry Clinic at the Sha'are Zedek Medical Center, Jerusalem, Israel.