LASIK eye surgery can
be an alternative to glasses or contact lenses done for the correction of
certain common vision problems.
LASIK (laser-assisted
in situ keratomileusis) is a type of laser refractive surgery — the best known and
most commonly performed. In general, a special type of cutting laser is used to
precisely change the shape of your cornea — the dome-shaped transparent tissue
at the front of your eye — to improve vision.
Normally, images are
clearly focused on the retina in the back of your eye because the light rays
are bent properly to contact the retinal surface. With nearsightedness
(myopia), farsightedness (hyperopia) or astigmatism, the light is bent
incorrectly and it ends up being focused elsewhere, resulting in blurred
vision. Traditionally, the blurred vision is corrected by bending (refracting)
light rays with glasses or contact lenses. But reshaping the cornea itself also
will provide the necessary refraction.
Why it's done
LASIK surgery may be
an option for the correction of one of these vision problems:
·
Nearsightedness (myopia). When your eyeball is slightly longer than normal or when
the cornea curves too sharply, light rays focus in front of the retina and blur
distant vision. You can see objects that are close fairly clearly, but not
those that are far away.
·
Farsightedness (hyperopia). When you have a shorter than average eyeball or a cornea
that is too flat, light focuses behind the retina instead of on it. This makes
near vision, and sometimes distant vision, blurry.
·
Astigmatism. When
the cornea curves or flattens unevenly, the result is astigmatism, which
disrupts focus of near and distant vision.
If you're considering
LASIK surgery, you probably already wear glasses or contact lenses. Your eye
doctor will talk with you about whether LASIK surgery or another similar
refractive procedure is an option that will work for you.
Risks
Complications that result in a loss of vision are very rare. But
certain side effects of LASIK eye surgery, particularly dry eyes and temporary
visual disturbances, are fairly common. These usually clear up after a few
weeks or months, and very few people consider them to be a long-term problem.
Before the procedure
Long-term results from LASIK tend to be best in people who are carefully
evaluated before surgery to ensure that they are good candidates for the
procedure. Your eye doctor will ask about your medical and surgical history and
give you a comprehensive eye examination.
In the eye examination, your doctor will evaluate your vision
and look for signs of eye infections, inflammation, dry eyes, large eye pupils,
high eye pressure and other eye-health conditions. He or she will also measure
your cornea, noting the shape, contour, thickness and any irregularities. This
helps your doctor assess whether you can undergo the procedure safely.
Your eye doctor also evaluates which areas of your cornea need
reshaping. He or she determines the precise amount of tissue to remove from
your cornea. Doctors generally use wavefront-guided technology to evaluate your
eye in detail before LASIK surgery. In this test, a scanner creates a highly
detailed chart, similar to a topographic map, of your eye. The more detailed
the measurements, the more accurate your eye doctor can be in removing corneal
tissue.
If you wear contact lenses, which can change the shape of your
cornea, you'll need to completely stop wearing them and wear only your glasses
for at least a few weeks before your evaluation and surgery. Your doctor will
provide specific guidelines depending on your situation and how long you've
been a contact lens wearer.
Before surgery, your doctor will discuss the risks and benefits
of LASIK, what to expect before and after surgery, and any questions you may
have.
After the procedure
Immediately after surgery, your eye might itch, burn and be
watery. You'll probably have blurred vision. You generally will experience
little pain, and you'll usually recover your vision quickly.
You might be given pain medication or eyedrops to keep you
comfortable for several hours after the procedure. Your eye doctor might also
ask you to wear a shield over your eye at night until your eye heals.
You'll be able to see after surgery, but your vision won't be
clear right away. It takes about two to three months after your surgery before
your eye heals and your vision stabilizes. Your chances for improved vision are
based, in part, on how good your vision was before surgery.
You'll have a follow-up appointment with your eye doctor one to
two days after surgery. He or she will see how your eye is healing and check
for any complications. Plan for other follow-up appointments during the first
six months after surgery as your doctor recommends.
It might be a few weeks before you can start to use cosmetics
around your eyes again. You might also have to wait several weeks before
resuming strenuous contact sports, swimming or using hot tubs.
Follow your doctor's recommendations about how soon you can
resume your normal activities.
Results
LASIK often offers improved vision without the hassle of glasses
or contact lenses. In general, you have a very good chance of achieving 20/25
vision or better after refractive surgery.
More than 8 out of 10 people who've undergone LASIK refractive
surgery no longer need to use their glasses or contact lenses for most of their
activities.