Eye Surgery

Keratoplasty

Under study for low to moderate farsightedness is a technique called radiofrequency thermokeratoplasty, in which radio-frequency energy heats and shrinks the cornea to reshape it and correct the vision problem. The procedure takes about five minutes per eye, depending on the amount of correction needed.

The technique is in the third phase of clinical trials, says Mitch Campbell, president of Refractec Inc. in Laguna Hills, California, which markets the Refractec Corneal Shaping System. Clinical trials of the technique are underway, and it could be available by 2001. The technique might also prove useful for eyes overcorrected by excimer laser surgery and for presbyopia and astigmatism, Campbell says.

Also under study is laser thermal keratoplasty by Sunrise Technologies International of Fremont, California, which shrinks the collagen in the mid-periphery of the cornea to achieve vision correction in a matter of seconds. It is designed to remedy farsightedness from .75 to 2.5 diopters, says Ed Coghlan, a company spokesman.

In late July, the Food and Drug Administration s Ophthalmic Devices Panel did not recommend approval for the Sunrise LTK laser system but recommended that the company provide additional data. Sunrise plans to pursue steps for approval.

One concern about keratoplastic procedures has been that the effect slowly subsides after a few years. McDonald doesn t see this as a problem, at least not for everyone. There is a place in refractive surgery for a quick and easy and cheap procedure that can be repeated every few years, she says; it will give people a chance to try out the technique.