A Lighter, Defter Touch
Years of refinement have made laser eye surgery better than ever
When Cindy Duong decided to pitch her contact lenses and have surgery last summer to correct her nearsightedness, she assumed she'd get LASIK. The procedure, in which a tiny flap is cut across the top of the eye's clear, dome-shaped cornea and folded back so a laser can reshape the tissue underneath, is easily the most common type of laser eye surgery, making up 87 percent of all procedures last year. But Duong's doctor said that the cornea in her left eye was too thin to both cut the flap and contour her cornea as LASIK (short for laser-assisted in situ keratomileusis) surgery requires. Instead, her doctor suggested she consider a procedure she'd never heard of called photorefractive keratectomy.
The PRK procedure doesn't entail a flap. Instead, the surgeon removes the very top layer of cells from the cornea, often by scraping them away after loosening them with alcohol, and then uses a laser directly on the exposed surface to shape it. Although the Food and Drug Administration approved PRK in 1995, a few years earlier than LASIK, the latter quickly surpassed PRK in popularity. That's because patients who had LASIK usually experienced clearer vision right off the bat and felt little pain or scratchiness in their eyes post-surgery. With PRK, the eyes generally take several days to heal comfortably, and vision remains blurry for the first few days or weeks.
Duong had PRK on her left eye and LASIK on her right. As expected, she noticed an immediate improvement in the vision in her right eye and felt no discomfort. Meanwhile, her left eye was irritated, and her vision was blurry for about a week. But then a funny thing happened. As the weeks passed, she noticed that her left eye caught up with and then surpassed the eyesight in her right eye. Her left-eye vision was slightly clearer, and she had fewer problems seeing at night. "Now, my PRK eye is much better than my LASIK eye," says the 26-year-old chemist from Chicago. "At night, there's definitely a blurriness in my right eye more than my left."
Duong isn't the only fan of PRK. Although LASIK remains the laser eye surgery of choice, in the past few years, more eye surgeons have been performing PRK. In some cases, they are turning away from LASIK entirely, say experts. Between 2005 and 2006, the percentage of all laser eye surgeries that were performed using PRK and other "surface ablation" techniques-in which tissue is ablated or removed from the surface of the eye rather than from the inside as it is with LASIK-rose from 8 percent to 13 percent, according to Market Scope, an ophthalmic research company. Meanwhile, the actual number of laser surgeries declined slightly during that time, from 1.41 million to 1.38 million. "Surgeons today are doing a higher percentage of PRK than in the past, and their mix is changing," says Dave Harmon, president of Market Scope.
Two other surface-ablation techniques, LASEK and Epi-LASIK, are essentially newer versions of PRK. Instead of removing the very top layer or "skin" of the eyeball, they push it to one side and then replace it following laser surgery on the surface of the cornea. Research is inconclusive, but many experts say these newer techniques don't actually reduce the discomfort caused by the surface ablation.