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. But the solutions are far from perfect. The new lens corrects distance vision and restores the ability to focus at all distances. The company hopes to start clinical trials in the United States this year, and the lens could be on the market within three years.