LASIK: Refractive Surgery for Vision Correction (cont.)
What are the risks and how can I find the right doctor for me?
Most patients are very pleased with the results of their refractive surgery.
However, like any other medical procedure, there are risks involved. That's why
it is important for you to understand the limitations and possible complications
of refractive surgery.
Before undergoing a refractive procedure, you should carefully weigh the
risks and benefits based on your own personal value system, and try to avoid
being influenced by friends that have had the procedure or doctors encouraging
you to do so.
- You may be undertreated or overtreated. Only a certain percent of
patients achieve 20/20 vision without glasses or contacts. You may require
additional treatment, but additional treatment may not be possible. You may
still need glasses or contact lenses after surgery. This may be true even if
you only required a very weak prescription before surgery. If you used
reading glasses before surgery, you will still need reading glasses after
surgery.
- Results are generally not as good in patients with very small amounts
of astigmatism or very large refractive errors of any type. You should
discuss your expectations with your doctor and realize that you may still
require glasses or contacts after the surgery.
- Results may not be lasting. The level of improved vision you
experience after surgery may be temporary, especially if you are farsighted
or currently need reading glasses. It is especially important for farsighted
individuals to have a cycloplegic refraction (a vision exam with lenses
after dilating drops) as part of the screening process. Patients whose
manifest refraction (a vision exam with lenses before dilating drops) is
very different from their cycloplegic refraction are more likely to have
temporary results.
- Some patients lose vision. Some patients lose lines of vision on
the vision chart that cannot be corrected with glasses, contact lenses, or
surgery as a result of treatment. There is little known about how refractive
procedures affect other aspects of vision, such as contrast sensitivity (the
ability to see objects clearly against a similar background or in dim
lighting conditions). Some studies suggest that patients do not see as well
in situations of low contrast, such as at night or in fog, after treatment
as compared to before treatment. Therefore, patients with low contrast
sensitivity to begin with probably should not have a refractive procedure.
It is important for you to know that not all eye centers test contrast
sensitivity, and that when it is tested, it should be done in a dark room.
- Some patients may develop severe dry eye syndrome. As a result of
surgery, your eye may not be able to produce enough tears to keep the eye
moist and comfortable. This condition may be permanent. Intensive drop
therapy and the use of plugs or other procedures may be required.
Additional Risks if you are Considering the Following:
Monovision
Monovision is one clinical technique used to deal with the correction of
presbyopia, the gradual loss of the ability of the eye to change focus for
close-up tasks that progresses with age. The intent of monovision is for the
presbyopic patient to use one eye for distance viewing and one eye for near
viewing. This practice was first applied to fit contact lens wearers and more
recently to LASIK and other refractive surgeries. With contact lenses, a
presbyopic patient has one eye fit with a contact lens to correct distance
vision, and the other eye fit with a contact lens to correct near vision. In the
same way, with LASIK, a presbyopic patient has one eye operated on to correct
the distance vision, and the other operated on to correct the near vision. In
other words, the goal of the surgery is for one eye to have vision worse than
20/20, the commonly referred to goal for LASIK surgical correction of distance
vision. Since one eye is corrected for distance viewing and the other eye is
corrected for near viewing, the two eyes no longer work together. This results
in poorer quality vision and a decrease in depth perception. These effects of
monovision are most noticeable in low lighting conditions and when performing
tasks requiring very sharp vision. Therefore, you may need to wear glasses or
contact lenses to fully correct both eyes for distance or near when performing
visually demanding tasks, such as driving at night, operating dangerous
equipment, or performing occupational tasks requiring very sharp close vision
(e.g., reading small print for long periods of time).
Many patients cannot get used to having one eye blurred at all times. The
difference between monovision with contact lenses and monovision with LASIK is
that you can always take contact lenses out or have them changed (the treatment
is reversible and adjustable) as opposed to LASIK, where the result of the
surgery is not reversible or adjustable. Therefore, if you are considering
monovision with LASIK, make sure you go through a trial period with contact
lenses to see if you can tolerate monovision, before having the irreversible
surgery performed on your eyes. Just before this trial period starts, find out
if you pass your state's driver's license requirements with monovision, or if
you need supplemental glasses to drive.
In addition, you should consider how much your presbyopia is expected to
increase in the future. Ask your doctor when you should expect the results of
your monovision surgery to no longer be enough for you to see near-by objects
clearly without the aid of glasses or contacts, or when a second surgery might
be required to further correct your near vision.
Bilateral Simultaneous Treatment
You may choose to have LASIK surgery on both eyes at the same time or to have
surgery on one eye at a time. Although the convenience of having surgery on both
eyes on the same day is attractive, this practice is riskier than having two
separate surgeries. The second eye may have a higher risk of developing an
inflammation if surgery is done on the same day than if surgery is performed on
separate days. If a malfunction of the laser or microkeratome occurs causing a
complication with the first eye, the second eye is more likely to also
experience the same complication if the surgery is performed on the same day
rather than on separate days.
If you decide to have one eye done at a time, you and your doctor will decide
how long to wait before having surgery on the other eye. If both eyes are
treated at the same time or before one eye has a chance to fully heal, you and
your doctor do not have the advantage of being able to see how the first eye
responds to surgery before the second eye is treated.
Another disadvantage to having surgery on both eyes at the same time is that
the vision in both eyes may be blurred after surgery until the initial healing
process is over, rather than being able to rely on clear vision in at least one
eye at all times.
Finding the Right Doctor
If you are considering refractive surgery, make sure you:
- Compare. The levels of risk and benefit vary slightly not only from
procedure to procedure, but from device to device depending on the
manufacturer, and from surgeon to surgeon depending on their level of
experience with a particular procedure.
- Don't base your decision simply on cost and don't settle for the
first eye center, doctor, or procedure you investigate. Remember that the
decisions you make about your eyes and refractive surgery will affect you
for the rest of your life.
- Be wary of eye centers that advertise, "20/20 vision or your money
back" or "package deals." There are never any guarantees
in medicine.
- Read. It is important for you to read the patient handbook provided
to your doctor by the manufacturer of the device used to perform the
refractive procedure. Your doctor should provide you with this handbook and
be willing to discuss his/her outcomes (successes as well as complications)
compared to the results of studies outlined in the handbook. Even the best screened patients under the care of most skilled surgeons can experience serious complications.
- During surgery. Malfunction of a device or other error, such as
cutting a flap of cornea through and through instead of making a hinge
during LASIK surgery, may lead to discontinuation of the procedure or
irreversible damage to the eye.
- After surgery. Some complications, such as migration of the flap,
inflammation or infection, may require another procedure and/or intensive
treatment with drops. Even with aggressive therapy, such complications may
lead to temporary loss of vision or even irreversible blindness.
Under the care of an experienced doctor, carefully screened candidates with
reasonable expectations and a clear understanding of the risks and alternatives
are likely to be happy with the results of their refractive procedure.
Advertising
Be cautious about "slick" advertising and/or deals that sound
"too good to be true." Remember, they usually are. There is a lot of
competition resulting in a great deal of advertising and bidding for your
business. Do your homework.
