Close laser shave for corneal scars.

Close laser shave for corneal scars

Laser treatments may someday make many corneal transplants unnecessary, new research suggests.

Preliminary results from clinical trial with excimer lasers indicate that the ultraviolet beams can shave layers of cells off the eye's clear outer coating, or cornea, leaving an unscarred, "exquisitely smooth surface," says Walter J. Stark, an ophthalmologist at the Johns Hopkins University School of Medicine in Baltimore. He suggests the technique may someday find broad application in removing sight-impairing corneal scars that result from injury or infection.

Widespread use of lasers to correct nearsightedness or farsightedness by reshaping the cornea remains farther down the road, he says. In most cases, those conditions are easily corrected with eyeglasses or contact lenses, and preliminary data suggest that many corneas rehsaped by laser revert to their former curvature, Stark says.

For corneal scarring, however, "we're very excited about the [technique's] potential," he says. Stark reports that 15 of the 19 people with corneal scars treated with an excimer laser in his study have regained enough visual acuity to avoid corneal transplants, at least for now. He suspects the treatment could postpone or replace corneal transplantation in 10 to 15 percent of patients now in need of the expensive transplant surgery, which is plagued by a shortage of donors.

It remains unclear how expensive the laser procedure might be. The machines aren't cheap, costing $250,000 to $350,000 each and requiring maintenance to the tune of $100,000 to $150,000 per year, Stark says. But he suggests the experimental technique could become cost-effective on a per-patient basis after FDA approves it for general use and patient volume increases. He expects such approval within four years.

Other researchers caution that ophthalmologists shouldn't jump on the laser bandwagon before the procedure is perfected and long-term data come in. They note that most sight-impairing corneal scars in U.S. patients today arose from damage incurred during cataract surgery years ago, before ophthalmologists had perfected that technique.