Laser Eye Surgery--A Popular Alternative

Laser Eye Surgery--A Popular Alternative

Laser eye surgery is intended for people who want to minimize their dependency on glasses or contact lenses. Laser surgery can provide vision correction similar to what would be obtained with glasses or contact lenses. People under the impression that surgery can improve their vision beyond what they can see with glasses or contact lenses, however, likely will be disappointed.

By far, the largest increase in laser eye surgery interest recently has been in a procedure called "laser in situ keratomileusis," popularly known as LASIK. Advertising for this technique appears prominently on broadcast outlets, including the Internet and in newspapers and magazines. Fortunately, says Terrence P. O'Brien, M.D., a spokesman for the American Academy of Ophthalmology (AAO), most surgeons and medical centers are doing a good job of educating the public about the risks and benefits of LASIK. "But patients need to be very well-informed in advance," he says.

LASIK permanently changes the shape of the cornea, and is performed for varying degrees of nearsightedness, farsightedness, and astigmatism. A surgical knife, called a microkeratome, is used to cut a flap in the cornea, leaving a hinge at one end of the flap. The flap is then folded back to reveal the middle layer of the cornea, called the stroma. Pulses from a computer-controlled excimer laser vaporize a portion of the stroma and the flap is then replaced. By removing this tissue, the shape of the central cornea is changed, and the refractive error is reduced.

O'Brien, who is also director of refractive surgery at the Wilmer Eye Institute at Johns Hopkins University in Baltimore, has performed over 10,000 eye surgeries. Still, he warns that people considering LASIK need to be wary of ads that make excessive promises.

"Price should not be the first factor" in considering to have delicate eye surgery, he says. "People fear blindness second only to cancer, and just as they wouldn't consider a discount open heart operation or budget brain surgery, they shouldn't take a chance with their eyes." The real struggle, he says, is in training doctors. "The most advanced technology and precise laser will give poor results if you don't have an experienced, capable surgeon."

This latest hype about LASIK's now-more-affordable advantage, coupled with some pretty appealing results, makes surgery one of the most exciting vision correction options available. Doctors say that LASIK gives a rapid visual recovery, with minimal pain, and little or no post-operative discomfort. In fact, most people who undergo LASIK, like Beth Polazzo--one of O'Brien's patients--can see well enough to drive immediately after surgery, and usually have excellent vision within a week.

"I had good vision immediately," says the 54-year-old Brooklyn, N.Y., resident, even though eventually one eye had to be retreated. "This is the best I've seen since I was seven years old." The laser does its work on each eye in less than a minute, and patients are typically back to work or normal activities within three days.

While most people are pleased with the results of their surgery, O'Brien says that, as with any medical procedure, there are risks involved. Some include: over- or under-treatment; the inability to wear contact lenses; permanent loss of vision; reduction in the quality of vision including the development of glare, halos, and starbursts; difficulty with night-driving; and reduced vision in dim lighting conditions. The risks are doubled when both eyes are treated at the same time.

Also, LASIK is not reversible. That's why in Polazzo's case, O'Brien intentionally undercorrected her distance eye. "We were aiming for modified monovision," he explains, which means that one eye would see close up while the other would be corrected to see distances. But Polazzo experienced some regression in her distance eye--that is, her distance vision began to worsen as she returned to nearsightedness--some weeks following surgery. However, because of the initial undercorrection, O'Brien was able to fix the problem.

A. Ralph Rosenthal, M.D., director of the Food and Drug Administration's division of ophthalmic and ear, nose and throat devices in the Center for Devices and Radiological Health, says that no one knows the long-term effects of laser eye surgery. "We just can't know that yet," he says, so when people call looking for a guarantee in years for the success of the procedure, "I can't give them one."

Before undergoing LASIK, Rosenthal says people should carefully weigh the risks and benefits based on what's important to them, and potential side effects, including the pros and cons of having one or both eyes done on the same day. It's also important to avoid being influenced by friends who have had LASIK surgery or doctors who encourage patients to do so.

A second laser procedure used today as an alternative to LASIK is photorefractive keratectomy, or PRK. Although O'Brien says that less than 5 percent of people undergo PRK, it is still the procedure of choice for certain eye conditions. This type of refractive surgery gently reshapes the cornea by removing microscopic amounts of tissue from the outer surface with a cool, computer-controlled ultraviolet beam of light. It does not, however, involve cutting. The procedure takes only a few minutes, and patients are typically back to daily routines in five to seven days.

Clinical studies indicate that about 5 percent of PRK recipients continued to need glasses for distance vision following the surgery, and up to 15 percent need glasses occasionally, such as when driving. In addition, many people experienced mild corneal haze following surgery, which is part of the normal healing process. The haze appeared to have little or no effect on final vision, and could only be seen by a doctor under a microscope. For about 5 percent of PRK patients, best-corrected vision without corrective lenses was slightly worse after surgery than before. These conditions, however, improved or disappeared in most people in six months.

Another new, less-invasive laser procedure--indicated for temporarily reducing hyperopia--is being aimed exclusively at people over 40. Laser thermal keratoplasty, or LTK, involves zapping 16 spots on the outer part of the cornea to shrink the tissue. People usually can leave 30 minutes after the procedure and resume normal activities the following day. The advantage of LTK is that it's a "no touch" procedure, meaning there's little chance of infection or loss of vision. The disadvantage is that the procedure is considered temporary since the treatment effect regresses--for many people, about half of the correction is gone within two years. Another drawback is that people may become nearsighted in the first six weeks, enough to require glasses for driving, and their vision can fluctuate for weeks after surgery.

Rosenthal wants people considering laser surgery to know and carefully weigh the pros and cons. "FDA mandated that manufacturers of all excimer lasers make available to people a patient information booklet," he says, that spells out this information. If the doctor fails to offer one, Rosenthal says that you should ask for it.

Experts say that the reliability of laser vision correction is quite good in mild to moderate levels of refractive errors. But people desperate for clear vision need to understand the dangers. The most satisfied laser surgery patient is one who has realistic expectations and a thorough understanding of the risks and possible complications of refractive surgery.