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October 11, 1999 R U
Ready To Dump Your Glasses?
Laser
surgery can work wonders but there are risks
Maybe you
don't mind the dents your glasses have carved into the sides of your nose.
Maybe you actually enjoy cleaning your contact lenses. But if you're anything
like the 160 million other people in the U.S. who wear contact lenses or
glasses, then you've probably occasionally wondered what your life would be
like with perfect vision. Oh, what a beautiful prospect! No more foggy
spectacles on winter days. No more fishing for dropped contacts in the
bathroom sink. No more misplaced glasses when you're rushing off to work. You could turn those dreams
into reality--in less than 15 minutes. Just settle onto the surgical couch at
an ophthalmologist's office and let an incredibly precise excimer laser
reshape your eyes, or more accurately your corneas. Then get up and
experience a bright new world. At least that's what doctors--and, more
important, their ecstatic patients--are saying about LASIK. That's short for
laser-assisted in situ keratomileusis), which could well become the most
popular elective surgery among baby boomers since they all had their tonsils
removed in the 1950s. Chances are you already know people
who have had their eyes--in that newest of buzz verbs--lasered. Nearly
500,000 Americans are expected to undergo the procedure in 1999--almost
double the number in 1998. For 7 out of 10 it worked spectacularly: it
corrected their vision to a very normal 20/20. Most of the rest still saw
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 in the U.S. until
just four years ago. Most patients aren't just
happy with the results; they're positively gleeful. "Everything is so
clear," says Yvonne Chapman, a registered nurse in Los Angeles who had
her corneas reshaped six months ago. "I still go into the bathroom
before bed every night to wash my hands and take my contacts out because I
think I have them in." Never mind that LASIK costs upwards of $2,500 an
eye and isn't covered by most insurance companies. We're talking about seeing
your toes in the shower! Still feeling unsure? Then
drive over to the Fair Oaks Mall in Fairfax, Va., outside Washington, and
watch through a plate glass window as surgeons at the Visual Freedom Center
perform the operation Mondays through Saturdays. Talk to the patients as they
walk out the door. They will tell you how excited they are to be finally
throwing away their glasses. 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 those 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, N.J. "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 less 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. Nearly all the excimer lasers used so far were actually 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. Two more types of excimers are expected to pass muster by
the end of this year. In the past
two 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. Our 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 needed--curving or flattening--to help focus the image
onto the retina, the light-sensitive tissue at the back of the eyeball that
converts the 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 eye's 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 retina--either 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
in the U.S., because the results were so difficult to predict and the healing
process was often slow and painful. Enter the excimer laser.
Originally 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 surgeons needed to rework the delicate tissues of
the eye. So a company called Summit Technology, of Waltham, Mass., dedicated
itself to figuring out how to adapt the excimer laser to eye surgery. Today,
Summit and another company, Visx, of Santa Clara, Calif., dominate the
eye-laser industry in the U.S. 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.
Although the epithelium always grew back, the cornea retained its new shape.
It was a big improvement over radial keratotomy, although the healing of the
epithelium 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 lifted 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's 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 Saran 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 substantially bothered 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, or a quarter of an inch.
So, as you might expect, patients whose pupils grow wider than the average of
about 6 mm 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 troublesome glare and halos. Since there are no guidelines
for LASIK, it's up to each physician to decide who is the best candidate.
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. Summit recently
acquired a start-up company that is working on a laser that uses radar
initially developed for the Star Wars, or Strategic Defense Initiative, to track
the eye during the operation. Currently doctors keep the eye steady by asking
you to stare at a blinking red dot. If you suddenly shift your gaze, your
surgeon can turn the laser off very quickly, but the doctor can't compensate
for the small, involuntary eye movements we make all the time. These saccadic
motions aren't usually a problem, but they may explain some of the
variability in results of the surgery. Another big advance in the
works could provide nearly all patients with better than 20/20 vision.
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 over
35 will need glasses to read and for 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 operation--and not just 15
minutes before--to examine your eyes as well as take 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. 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 vision--even with contacts or glasses--than they
did before the surgery. For top doctors the figure is under 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 improvements that future technology
will bring.
I’m Still Waiting For My Miracle A Cautionary Tale BY VIVECA NOVAK Nobody wants to be an anomaly
when it comes to medical matters, the kind of patient who prompts doctors to
shake their head and say softly, "I've never seen this before." I had followed advances in
vision-correcting surgery for more than a decade. My eyes were awful. I had
glasses as a young child, contacts as a teenager, but lately I could wear
only an exotic and costly kind of lens. Glasses didn't work as well. Allergy
season was a nightmare. And yes, I had always dreamed of being able to wake
up and read the clock across the room, to swim and see who was hanging around
poolside. But I was also apprehensive--bad eyes are better than worse eyes,
and there were some early horror stories. Then lasers came on the scene,
with little but rosy reports. I began to think it was time. I went to three
doctors to be sure I was a good candidate. I called every friend-of-a-friend
who'd been through it; all were elated, except one worrisome soul who
developed a scary condition called "Sands of Sahara." But my
doctor, a respected and decent guy, soothed me, told me I'd be fine. He
pulled out the charts of his many delighted patients, saying he'd sent more
than 200 to have it done. The LASIK surgeon he sent me to, perhaps the most
experienced in the Washington area, has reshaped thousands of corneas. I was more excited than
scared. The procedure wasn't painful. It was over in 10 minutes. It was worse
for my husband, who watched close up on a TV monitor and said it was almost
as bad as watching my caesarean. I went home, took a nap, woke up--and could
see the clock across the room. At the doctor's the next day, I was seeing
20/20 with my left eye, 20/40 with my right. But instead of getting better,
as my doctor predicted, my vision worsened. I was told my corneas were
extremely dry, and I should apply artificial tears every couple of hours.
Then the surgeon was called in; he suggested I use the drops more often,
about every 15 minutes. This wasn't especially practical for a journalist--no
interviews longer than a quarter-hour and never mind the eye makeup, among
other things--but I tried to stick to the schedule. It didn't do the trick. Next we tried plugging my tear
ducts (outgoing, not incoming) to keep my eyes moist. A little improvement,
which reversed when the temporary plugs dissolved. Another round hasn't
helped much. The next step is permanent plugs, supposedly to create a tighter
seal. I'm still soaking up bottled tears like an ocular desert and putting
moisture goop in my eyes every night. And that's where things stand
now. It has been two months since the surgery. My doctors keep saying they're
confident my eyes will improve with time--but they also say my experience is
extremely unusual (one of them says he's never seen this problem in anyone
else), so I'm not sure they know what will happen. A third doctor I consulted
said there was nothing wrong surgically, and he too thinks my condition will
get better. But here's the worst part: my
vision now can't be improved, except marginally, with glasses. The problem is
on the surface of my eye, which isn't what lenses correct. One doctor likens
it to scratches on the crystal of a watch. My eyes were always a little dry,
but nobody seems to understand why they now need dramatically more moisture. On some days I'm pretty sure
my story will have a happy ending. On others, though, I look at my children,
ages 3 1/2 and 14 months, and wonder if I'll ever see them in crisp focus
again. I'm devastated that reading has become a chore, not a pleasure; some
days I can't make out the newspaper until the afternoon, when my vision
sometimes sharpens. I don't drive in unfamiliar
terrain, because I can't read road signs until I'm on top of them. I'm
constantly testing myself. Can I read that ad on the other side of the subway
car? Can I see that license plate in front of me? How hard is it to read the
daily Hotline on the Internet? I'm delighted that nearly
everyone else who has this procedure feels like a lottery winner, only more
so. I hope that within a few months I can join them. Friends and
acquaintances who contemplate going under the laser ask me how it went,
expecting the usual sunny response. Unless things turn around, if I had it to
do over again, I wouldn't. But believe me, I understand the lure of that pot
of gold, the promise of a lifelong wish granted. So to those who feel they
have to join this almost universally happy club, I can't say don't. Just do
it with eyes wide open.
November 01, 1999 Letters The
Laser Fix Great steps forward in
technology and medicine--the LASIK procedure is undoubtedly one of them--will
always carry some risks. Our patients need accurate information like your
report in order to make an informed decision. My eyesight before LASIK was
about 20/900--which amounts to being legally blind. Three weeks after LASIK,
I am at 20/50. I'm using artificial tears pretty regularly, but I am thrilled
that I can see what I could not before. Was I expecting better? Sure! Am I
satisfied? You bet! Much of what has been written
about LASIK has hyped the procedure without addressing the potential risks. I
had LASIK done two years ago, and my vision improved afterward. But gradually
it deteriorated, and the dry-eye syndrome set in. Luckily my vision can still
be corrected with glasses, which I wear for driving and movie viewing. Look
long and hard before you leap. The facts can be disguised by the enthusiasm. I was able to read your
article sans glasses after going from 20/200 with an astigmatism to 20/15 in
both eyes, thanks to LASIK. Was it uncomfortable? Slightly. Is it amazing?
Absolutely. To be able to see my children in the water at the beach is truly
wonderful. Could I afford it? No way. So to my incredible mother who gave me
(and my sister) the gift of sight after 20-plus years, I say, "You are
the most beautiful woman I have ever seen." Treating myopia with corneal
surgery is like treating obesity with liposuction. Corneal surgery is an
elective procedure that carries the risk of serious and permanent
complications. Corneaplasty, now in FDA trials, could carry fewer risks.
While both corneaplasty and corneal surgery are treatments for refractive
errors, neither is a cure for myopia. You cannot treat myopia comprehensively
just by altering the shape of the cornea. High tech may be glamorous, but it
is not always the best medicine. You did an excellent job in
presenting both sides of laser eye surgery. As an optometrist, I am not
recommending this procedure. History will teach us that the cornea is not a
structure we can mess around with. The risks (e.g., current surgical mishaps
and potentially devastating long-term complications) are simply not worth it. |
