25 Years in Myopia: Surgical Advances Improve Vision

Normal Sight Nears

A few American surgeons flew to the then-Soviet Union to observe, and the techniques they brought back were altered to improve safety. Standardized diamond-tipped tools they developed helped as well.

By 1984, radial keratotomy was still considered controversial.

But the promise was there, recalled Dr. Robert Maloney of the Jules Stein Eye Institute at the University of California Los Angeles.

His typical conversation with a patient considering the procedure in 1984 would go something like this:

"The operation usually doesn't lead to 20/20 vision, but we can usually reduce your nearsightedness enough that you can drive a car without glasses during the day.

"However, night driving can be hindered by severe glare from the incisions. Risks of the operation include perforation of the eye if the incisions are made too deep, and farsightedness if we overshoot.

"You will have a lot of pain for a week, and your vision will be blurry for several weeks."

The first real clinical trial -- PERK (Prospective Evaluation of Radial Keratotomy) -- published positive results in 1985, but Salz, one of only 10 U.S. surgeons who participated in that trial, remembered taking a lot of criticism for it.

Then word came of an investigational method using lasers to make the cuts, he recalled.

"We went to see the first laser patients in New Orleans in about 1988/1989," Salz told MedPage Today. "It was exciting to see eyes that looked normal."

Whereas radial keratotomy left scars in the cornea that created glare and halos, laser procedures left virtually no mark.

Focus on Innovation

Outside the U.S., a parallel line of research had been underway that would make refractive surgery possible for patients like Nancy with high-order refractive errors.

One research group would remove a small part of a myopic cornea, freeze it, and essentially lathe it into a shape that would resolve the refractive error before reattaching it, Pepose said.

Although this approach never gained popularity, it did lead to development of precision instruments called keratomes or microkeratomes to remove thin slices of cornea, he noted.

Then researchers realized that lasers could do the same thing more accurately, leading to the birth of photorefractive keratoplasty (PRK) and then LASIK, as laser-assisted in situ keratomileusis is more popularly known.

By 1995, the excimer laser gained FDA approval for surface treatments, setting off an explosion in the number of refractive procedures done.

"The procedure has just gotten better and better and better," Salz said in an interview.

One major step forward was computer mapping of the exact topography of the cornea, Pepose explained. Wavefront-guided procedures now allow treatment of astigmatism and higher-order aberrations, he said.

Nancy's high diopter myopia almost made her a candidate for the newest treatment for myopia, artificial implants placed on top of the natural lens, which Pepose described as "almost like implantable contact lenses."

These intraocular lenses haven't caught on much yet in the U.S. because of concern about long-term outcomes but may be the future of myopia treatment with further advances, Asbell said.

However, Nancy's cornea was thick enough to allow LASIK using a technique that removes less tissue, which Dr. Salz performed late last year.

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