You could turn those dreams into realityin less than 15 minutes. Just settle onto the surgical couch at an ophthalmologist's office and let an excimer laser reshape your eyes, or more accurately your corneas. Then get up and experience a bright new world. At least that's what doctorsand, more important, their ecstatic patientsare saying about lasik. That's short for laser-assisted in situ keratomileusis, the elective surgery that is fast becoming as popular among well-to-do Asians as it is among Americans.
Chances are you may know people who have had their eyesin that newest of buzz wordslasered. Nearly 500,000 Americans underwent the procedure last year, almost double the number in 1998. Clinics in Taiwan perform 1,000 lasik operations a month; in Japan, doctors estimate 30,000 people will get lasered this year. The Asian market for lasik is potentially vast: 60% of Japanese suffer impaired vision, as well as more than half the population of Hong Kong. An estimated 95% of Taiwan's hard-studying college students are nearsighted. Prices in Asia are often around half the $2,500 per eye that surgeons in the U.S. charge for the procedure. In Thailand, where the Tourism Authority is promoting the country as a destination for low-cost, quality medical services, lasik goes for as little as $600 an eye. In India, doctors charge as little as $160 per eye.
In the U.S., 70% of lasik patients have had their vision corrected to a very normal 20/20. Most of the rest still see well enough to drive without corrective lenses. By 2010, some surgeons predict, lasik will have advanced so far that 90% of patients will see better than 20/20. That's impressive for surgery you couldn't get until recently.
Now for the reality check. "lasik is a surgical procedure with all the attendant risks of any surgical procedure," says Dr. Mark Mannis, a professor of ophthalmology at the University of California at Davis, who has performed the operation on a weekly basis for the past four years. "It is highly successful in the vast majority of well-chosen cases, but"and here you have to pay close attention"each of those words I said is very important." The best candidates, he emphasizes, are adults whose sight is only moderately distorted, whose vision is stable and who have no other eye problems. Even so, complications occur that can't always be corrected.
It's also important to realize that 20/20 vision isn't synonymous with perfect eyesight. The standard eye chart measures vision under conditions in which contrast is high. But there are other factors, like how well you see in dim light or discriminate among various shades of gray, that help determine the overall quality of your vision and that can be adversely affected by lasik.
Just ask Steven Assennata of East Brunswick, New Jersey. "If I had understood there was a chance I would be worse off, I might have changed my mind," he says. lasik corrected his eyesight to 20/20 all right, at least in one eye, but left him seeing double and ruined his night vision so that he can no longer drive after dark. The worst part, he says, is knowing he didn't need the surgery. Although his contacts were becoming a nuisance before the operation, he could have seen fine through admittedly thick glasses. Assennata's doctor says he was made aware of the risks.
There are no reliable statistics on people like Assennata who suffer serious post-lasik complications. Estimates range from fewer than 1% of patients of corneal specialists to as high as 5% of patients of less experienced ophthalmologists. An additional 10% to 15% of patients must undergo a second lasik procedure to get their correction right. These repeat procedures are considered "enhancements" rather than complications, but they do require another round of cutting and lasering. And in the absence of a long track record for the procedure, no one can guarantee that other problems won't crop up in 10, 20 or even 30 years.
lasik is, after all, a young technology. In the U.S., nearly all the excimer lasers used so far were approved by the Food and Drug Administration for a different type of eye surgery. (Doctors are allowed to adapt certain existing technologies to new uses.) The first excimer laser specifically designed for lasik wasn't approved by the fda until July 1998.
In the past couple of years, there have been some dramatic improvements in lasik technology. And that, no doubt, helps explain why so many eye surgeons have chosen to undergo the procedure themselves. But is lasik right for you? To answer that, it pays to know a little physiology.
Your eyes are surrounded by a tough, protective layer called the sclera. Only at the front of the eyeball does the sclera give way to the cornea, which is transparent. Light passes through the cornea to the pupil, the hole in the middle of the iris, or colored part of your eye. Depending on how bright the incoming light is, the pupil grows wider or narrower, much like the adjustable aperture of a camera. The light then passes through the lens, which lies directly behind the iris and changes shape as neededcurving or flatteningto help focus the image onto the retina, the light-sensitive tissue at the back of the eyeball that converts light into electrical signals. From there, the optic nerve sends these impulses to the brain's optic centers, which create the picture in your mind.
As it happens, the lens provides just a third of the eye's focusing power. The rest comes from the cornea, which acts like a second lens to help focus light onto the retina. If you're nearsighted, or myopic, your eye produces clear images of nearby objects or people. But light from distant sources is focused on a point somewhere in front of your retinaeither because the curve of your cornea is too steep relative to the length of your eyeball, or the eyeball is too long relative to the corneal curve. If you're farsighted, or hyperopic, on the other hand, the focal point for distant objects is fine, while the one for close sources actually falls behind the retina. In this case, the cornea is too flat relative to the length, or vice versa. Astigmatism occurs because the cornea's curvature is not uniform, making both distant and nearby objects blurry.
Age adds another complication. Most people, as they get older, need reading glasses or bifocals for close work. This condition, called presbyopia, is different from farsightedness because it has nothing to do with the shape of the eye; it happens when the lenses in the eyes lose their ability to curve sufficiently to focus on nearby objects.
Attempts to change the way the cornea focuses light by surgically altering its surface began as early as the 1950s. By the 1970s Soviet doctors routinely used scalpels to reshape the corneas of nearsighted patients in an operation called radial keratotomy. But the surgery, involving a spokelike ring of incisions, never really caught on: results were difficult to predict and the healing process was often slow and painful.
Enter the excimer laser. Developed in the 1970s for the precise etching of computer chips, it is a so-called cool laser, meaning that it can cut through almost any material without generating a lot of heat damage. That's just the kind of exacting low-impact tool that surgeons needed for working on the delicate tissues of the eye. So a U.S. company called Summit Technology dedicated itself to figuring out how to adapt the excimer laser to eye surgery. Today Summit and another American firm, Visx, dominate the eye-laser industry.
Eye surgeons first tried using the excimer laser to correct vision in a procedure called photorefractive keratectomy. They scaled off the cornea's outermost protective layer, or epithelium. Then they vaporized some of the underlying tissue with the laser, forcing the cornea to flatten or steepen, depending on the correction. The epithelium always grew back, but the cornea retained its new shape. It was a big improvement over radial keratotomy, though the healing remained painful.
lasik solved this problem. Using a delicate cutting instrument called a microkeratome, surgeons made a sideways slice through the cornea's outermost layers, leaving one side attached, and carefully lifted the flap of tissue out of the way. In nearsighted patients, an invisible beam of laser light then trimmed away layers of tissue from the center of the cornea, producing a flatter curve. In farsighted patients, the beam scooped out a doughnut-shaped ring that resulted in a steeper curve. Then the doctors put the flap back into place. After a few minutes of drying, it rebonded with the rest of the cornea. Because tissue destruction is minimal, there is little healing and much less pain. Patients see clearly almost immediately after the operation.
Provided the surgery is successful, of course. There is always a tiny risk of infection. Or the surgeon could accidentally slice off the corneal flap entirely, or replace it in such a way that it develops wrinkles. Imagine trying to see through crinkled plastic wrap, and you get an idea of what can happen if something goes wrong. In the worst cases, as in Assennata's, the aberrations are so extensive that they cannot be corrected, even with glasses.
Nearly everyone who undergoes lasik experiences at least some glare and halos, usually at night or under fluorescent lights. This occurs because the pupil widens in dim light, allowing incoming light to pass through both the corrected and uncorrected sections of the cornea, creating either a blinding or a hazy image. The problems usually diminish within six months. The best guess is that 5% of patients continue to be bothered substantially by glare and halos over the long term.
Most of the lasers currently used for lasik can sculpt an area no wider than 6.5 mm. So, as you might expect, patients whose pupils grow especially wide in the dark often have the biggest problems. An equally critical factor, however, is the amount of correction you need, measured in negative (-) diopters for nearsightedness and positive (+) diopters for farsightedness. The greater your correction, the more abrupt the transition zone between the sculpted and unsculpted portion of the cornea, and the greater the risk of glare and halos.
Since there are no guidelines for lasik, it's up to each physician to decide who is the best candidate for surgery. Many refuse to operate on patients with normal-size pupils whose correction is greater than -12 for nearsightedness and +4 for farsightedness. Others will go as high as -15 or +6.
Some of these limits may change in the next decade as the technology improves. Today's lasers, and the computer programs that run them, assume all corneas are more or less spherical. Scientists are developing instruments that will map the entire surface of the cornea and make point-by-point alterations to smooth out individual aberrations. Such carefully customized reshaping of the cornea could make astounding improvements in vision more of a sure thing.
But perhaps you don't want to wait five to 10 years longer for such improvements. If so, there are several things you can do to maximize your chances of success with today's lasik procedure:
--Don't get caught up in the hype. If you expect never to need glasses or contacts again, you may be disappointed. And since lasik can't correct presbyopia, most patients older than 35 will need glasses for reading and close work. You're also likely to need glasses at night or in movie theaters.
--Take your time to find the right physician. Do you feel comfortable with the doctor's explanations? Or are you getting pressured by a sales pitch? Insist on an ophthalmologist who will meet with you before the operationand not just 15 minutes beforeto examine your eyes as well as look at your medical history and answer your questions. Be sure to tell the doctor if you or anyone in your family has ever had a corneal disorder, diabetes or an autoimmune disease. Such conditions may increase the chances that laser surgery will severely damage your eyesight. If you have particularly dry eyes or an ocular herpes infection, you aren't a good candidate either. If the first surgeon turns you down, don't go shopping for another.
--Find out how much lasik training your doctor has. Some ophthalmologists apparently start zapping corneas after little more than a weekend seminar. That might be enough preparation for a surgeon who is already skilled, but you may decide to select a more experienced doctor, such as a cornea specialist who has completed a year or two of additional training. Early studies also showed that the complication rates for individual surgeons underwent two significant drops, after 300 and 600 procedures. Proponents will tell you that lasik training and technology are much better now and that today's doctors are perfectly proficient after just 25 to 50 operations. Also, if the doctor won't tell you what his or her complication rate is, find another one. Ask how many of the doctor's patients have worse visioneven with contacts or glassesthan they did before the surgery. For top doctors the figure is less than 3 in 1,000.
--Think long and hard about why you want to have your eyes lasered. "This is surgery on the only pair of eyes you have," says Dr. George Waring, founder of the Emory Vision Correction Center in Atlanta. Only you can decide whether the benefits are worth the small but very real risk of irreversible damage to your eyesight. If you're satisfied with your glasses or contacts, then you're better off leaving well enough alone. You can always change your mind later, when you've had a chance to weigh the even brighter future that improving technology may bring.
Reported by Dan Cray/Los Angeles, Wendy Kan/Hong Kong, Stella Kim/Seoul, Alice Park/New York, Maseeh Rahman/New Delhi, Don Shapiro/Taipei and Hiroko Tashiro/Tokyo
Write to TIME at email@example.com
TIME Asia home
Quick Scroll: More stories from TIME, Asiaweek and CNN
|Back to the top||
© 2000 Time Inc. All Rights Reserved.
Terms under which this service is provided to you.
Read our privacy guidelines.