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BEYOND GLASSES:THE LATEST LASER EYE SURGERY
If I had been born a slave during the Roman Empire, I would have been considered defective and sold at a discount. I was 5 when our kindly family optometrist diagnosed "progressive myopia" - galloping nearsightedness. Twelve years later, he wrote on my college medical form "fingers at ten feet" to describe my off-the-chart vision. In 20/20 terms - "20/20" being average-my eyesight was worse than 20/1,200. What most people see at 1,200 feet-four football fields-I couldn't see clearly at 20. About 100 million Americans are nearsighted, although only 10 percent of those are visually impaired as I was. In a normal eye, which works like a camera, the light streams through the clear cornea and lens (the focusing elements of the eye) and travels to the retina (the film), which processes the image and sends it to the brain. But with myopia, the eyeball itself is elongated and/or the cornea is too steep or shaped like a football instead of a basketball (which causes astigmatism as well as myopia). The light does not enter the eye correctly, so the image falls short of the retina and the brain perceives distant objects as blurry. In hyperopia-farsightedness-the eyeball is too short, the image overshoots the retina, and anything close is unclear.
Such refractive errors are expressed in diopters - which measure how much the light must be bent in order for images to land directly on the retina. When an optometrist (O.D.) or ophthalmologist (M.D.) writes a lens prescription, a "minus" number indicates nearsightedness, a "plus" farsightedness. (Second and third numbers, if any, denote the degree and direction of an astigmatism.) The bigger these numbers, the worse your uncorrected vision. For example, I was a minus eleven. Glasses and contacts corrected my vision, in effect, by altering the way light entered my eyes. Laser surgery did the same thing by changing the shape of my corneas.
DO I SEE PERFECTLY NOW? NO, BUT I'M LlKE SOMEONE who's been in a wheelchair her whole life and now walks with a slight limp. I'm still one diopter near-sighted, but I don't need reading glasses (no mean feat at 53!) and, except for night driving, I function with out any vision correction. All the same, refractive laser surgery is hardly as simple and risk-free as the ads and infomercials would have us believe. But if you're nearsighted, have tried contacts, and don't like glasses, it's certainly worth investigating.
The technology that made my surgery possible-the excimer laser-was invented by military physicists in the late seventies and refined in the early eighties at IBM to etch computer chips. So exact was its cool ultraviolet beam, the excimer also could "etch" a human hair, 50 microns thick, a fifth of a micron at a time. Dr. Trokel of Columbia, who visited the IBM labs in 1983-reportedly toting a bucket of cow eyes-was the first to write a paper suggesting the excimer's potential as a tool for sculpting corneal tissue without scarring or damaging the surrounding area.
Partly because the technology itself was so stunning and partly because the nation's 16,000 ophthalmologists were feeling the squeeze of managed care, a natural marriage transpired between eye surgeons and industry. Radial keratotomy (RK), in which a surgeon flattens the cornea by cutting spokelike slits with a scalpel, had already demonstrated that some types of nearsightedness could be corrected surgically. But photorefractive keratectomy (PRK), the procedure Trokel suggested, promised far greater accuracy. Like RK, PRK flattens the optical zone but does it with the precise ultraviolet pulses of the excimer. In 1987, after experimenting on animals and blind eyes, Dr. McDonald did the first PRK on a healthy but nearsighted human eye. The rest, as they say, is history.
BY THE EARLY NlNETIES, EXCIMER-DRIVEN SURGERY WAS BEING hawked aggressively throughout the world, touted as the greatest innovation in eye-care history. In late 1995, buoyed by early clinical trials-with 95 percent of PRK patients achieving 20/40 vision or better the FDA gave the green light to two companies, Summit and Visx, to market their excimers. Doctors were allowed to perform PRK on patients with mild to moderate nearsightedness (up to minus seven diopters) and with no more than minus 1.5 astigmatism.
By then, a smattering of surgeons, eager to treat higher myopes, had begun experimenting with LASIK, which combined PRK (the "zap") with microkeratome surgery (the "flap"), a technique ophthalmic surgeons had been using since the sixties. Instead of ablating the surface, or epithelium, of the cornea, LASIK reshapes only the tissue underneath the flap. Officially, LASIK is done under "practice of medicine" rules, which permit doctors to use FDA-approved technology in new ways, as long as it is in an individual patient's best interests.
According to industry watcher Irving Arons, managing director of Spectrum Consulting, approximately 100,000 refractive laser surgeries (including both PRK and LASIK) have been performed since FDA approval-far short of early projections, which estimated between 300,000 to 500,000 a year by now. "It's taking longer because of the FDA restrictions, the need for training doctors, and the cost," Arons explains. Each machine costs half a million dollars to buy, and about $60,000 a year to maintain. With such high overhead-and the controversial $250 "royalty fee" paid to Summit and Visx, which jointly profit every time a doctor zaps an eye-doctors need between 550 and 600 eyes a year just to break even, and 760 to 800 to realize a profit, according to Dr. Kenneth P. Taylor, director of the medical-and-ophthalmic-consulting unit at Arthur D. Little, Inc.
PRK retails for between $1,350 and $2,500 per eye, LASIK slightly more, and most insurance companies won't reimburse, deeming this "cosmetic" surgery-a point someone in my shoes would be quick to argue. In any case, for high myopes like me, cost is not a factor. Considering the cost of a couple of pairs of expensive glasses and contacts and all the paraphernalia needed to maintain them, the investment is made back in no time.
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