Laser Surgery Can Improve Vision Problems
Laser vision surgery is a popular treatment of vision problems. It reduces or eliminates
the need for eyeglasses or contact lenses.
Laser procedures can help correct refractive errors, or problems caused by an imperfectly
shaped eyeball or cornea. The cornea is the front, transparent part of the eye that
bends and focuses light. Refractive errors cause light from an object to be imprecisely
focused on the retina of the eye. This causes a blurred image. Refractive errors usually
occur in otherwise healthy eyes.
These are the 4 basic types of refractive errors:
Nearsightedness (myopia). Close objects appear sharp, but those in the distance are blurred. The eyeball is
longer than normal from front to back or the cornea is curved too much. Images focus
in front of the retina instead of on it.
Farsightedness (hyperopia). Distant objects can be seen clearly, but objects up close are blurred. The eyeball
is shorter than normal or the cornea is too flat. Images focus behind the retina.
Astigmatism. Objects are blurred at any distance. The cornea, lens, or both are shaped so that
images aren't focused sharply on the retina.
Presbyopia or aging eye. The eye loses its ability to change focus because of the natural aging process. This
usually occurs between ages 40 and 50. Refractive surgery cannot correct this problem.
It can make distance vision clearer, but it may make near vision worse.
LASIK (laser in-situ keratomileusis) makes up 90% to 95% of all laser vision correction
surgery and has the broadest range of uses. LASIK is a procedure that permanently
changes the shape of the cornea, the clear covering of the front of the eye. A knife
called a microkeratome is used to cut a hinged flap in the cornea. This flap may
also be created with a special laser designed for this procedure. The flap is folded
back revealing the stroma. This is the middle section of the cornea. Pulses from a
computer-controlled excimer laser vaporize a portion of the stroma and the flap is
replaced. Intralase uses a laser to create the flap resulting in a thinner flap allowing
for higher prescriptions to be corrected.
PRK (photo refractive keratectomy) uses a laser to remove the cornea's outer covering
and reshape it. This type of refractive surgery gently reshapes the cornea by removing
tiny amounts of tissue from the outer surface. Recovery takes a bit longer than it
does with LASIK.
LASEK (laser epithelial keratomileusis) is a surgery that combines LASIK and PRK techniques.
It may be used for people who cannot have LASIK. The cornea's surface is loosened
with an alcohol solution and moved aside before a laser reshapes the cornea. No flap
LTK (laser thermal keratoplasty) is a less invasive laser procedure to correct farsightedness
and astigmatism. LTK uses heat to reshape the cornea. The advantage of LTK is that
it's a "no touch" procedure. This means there's little chance of infection or loss
of vision. This technique is being performed less often than in the past.
Is refractive surgery for you?
Health insurers rarely pay for this type of surgery, which is considered cosmetic.
Although prices vary — from $300 to $2,400 per eye — experts warn that cost shouldn't
be your only concern.
Laser surgery may not be right for you. These are factors that indicate you are not
a good candidate:
You aren't a risktaker. Some people do have complications. No long-term data are available for current procedures.
It will affect your career. Check with your employer, military service, or professional organization, before
undergoing surgery. Some jobs ban certain refractive procedures.
You required a change in your contact lens or eyeglass prescription in the past year.
This is called refractive instability. People likely to have refractive instability
include those in their early 20s or younger; those whose hormones are fluctuating
because of a disease like diabetes; women who are pregnant or breastfeeding; and those
who are taking medicines like steroids.
You have a disease or are on medicines that may affect wound healing. Illnesses include autoimmune diseases, like rheumatoid arthritis, HIV, and diabetes.
Medicines include retinoic acid and steroids.
You have an eye disease.
You participate in contact sports, like boxing, wrestling, or martial arts, in which blows to the face and eyes are
You are not an adult. No lasers are approved for children or teens under 18.
Besides the illnesses listed above, other diseases may negatively affect the outcome
of LASIK surgery:
Herpes simplex or herpes zoster (shingles) around the eye area
Glaucoma, ocular hypertension, or are at risk for glaucoma
Eye injuries or previous eye surgeries
Keratoconus, a thinning disorder of the cornea
These are other risk factors that may affect the outcome of your surgery:
Large pupils. Younger people and people on some medicines may have large pupils in
dim light. This can cause glare, halos, starbursts, and double vision after surgery.
The symptoms may be severe enough to hamper normal activities like driving.
Thin corneas. Refractive surgery done on a cornea that is too thin may lead to blindness.
Previous refractive surgery. Talk to your healthcare provider if you've had RK, PRK,
LASIK or another refractive procedure. Additional surgery may not be recommended.
Dry eyes. LASIK surgery can worsen this condition.
Under- or over-correction can occur if too little or too much tissue is removed.
Astigmatism can occur if an uneven amount of tissue was removed.
Glares, halos, or double vision can result.
Finding a good surgeon
Only ophthalmologists are permitted to do LASIK. Ask your eye healthcare provider
or optometrist for a referral to an ophthalmologist who does LASIK. Ask for a referral
from an ophthalmologist who does not do refractive surgery. You can also visit the
American Academy of Ophthalmology's website, which offers a list of its members who do LASIK. Ninety-five percent of all ophthalmologists
are AAO members. Ask your surgeon the following questions:
How long have you been doing LASIK surgery?
How much experience do you have with the LASIK procedure?
How do you define success? What's your success rate?
What is the chance for me (with my correction) to achieve 20/20?
How many of your patients have achieved 20/20 or 20/40 vision?
How many patients return for enhancements?
Which laser will you be using for my surgery?
What's involved in after-surgery care?
Make sure your surgeon is using a laser approved by the FDA. The FDA has approved
5 lasers for LASIK. They are manufactured by VISX, Summit, Bausch and Lomb, Nidek,
Many people don't have 20/20 vision after surgery, but most are 20/40 or better. Eight
percent to 10% need an added procedure. Some need eyeglasses or contact lenses to
make up for over- or under-correction.
The complication rate is around 10%.
If you're a good candidate for a LASIK procedure, have realistic expectations, and
choose the right surgeon, chances are very good that you will do well.