Q:
I’m nearsighted, and tired of wearing glasses. Is laser eye surgery
safe? – J.R., 26
A: Generally, yes. Here's how it works: Nearsightedness occurs either when your cornea, which helps focus light, is too powerful, or when the distance from the cornea to the retina is too long, so that light focuses in front of, rather than onto, the retina. It's like having a movie screen too far back from the projector - the image is blurred. Laser surgery flattens the curve of the cornea, allowing light to focus more precisely.
The most
popular techniques are PRK (photorefractive keratectomy) and LASIK (laser
in-situ keratomileusis). With PRK, a surgeon removes tissue from the surface
of the cornea; with LASIK, she cuts a flap in the cornea and removes tissue
from beneath it. LASIK has some advantages: There is less pain afterward (most
of the nerve endings in the cornea are on the surface), vision returns to normal
faster, and fewer follow-up visits are required. Still, some surgeons prefer
PRK because the technique is simpler to perform.
Both PRK
and LASIK are outpatient operations done under local anesthesia. They take less
than ten minutes. About 95 percent of patients will gain at least 20/40 vision
(good enough to pass a driver's-license vision test); 70 percent will have
20/20 vision (commonly considered perfect). After surgery, patients may have
blurry vision or be extra-sensitive to light and glare. With LASIK, these problems
generally last a few hours to a few days; after PRK, they may last weeks or
months while the top layer of the cornea heals. Extremely rarely (in fewer than
one percent of cases), patients may have corneal scarring, which can cause
vision that's worse than before surgery. LASIK has a track record of fewer
complications, but when problems (such as infection of the corneal flap)
occur, they can be more serious than those resulting from PRK.
If your
vision prescription hasn't changed in at least a year, you're a good candidate
for laser surgery. Choose a surgeon who has done at least 1,000 operations and
performs several hundred each year. It costs around $5,000 to treat both eyes
with either PRK or LASIK. They're rarely covered by health insurance.