Laser vision correction of the eye is a precise,
minimally invasive laser treatment that reshapes the cornea, helping
your eye to focus properly. It can reduce or eliminate the need for
contact lenses or eyeglasses. This treatment is performed with an
excimer laser, which has been thoroughly tested and clinically proven.
In fact, since the United States Food and Drug Administration (FDA)
approved the procedure in October 1995, more than 1,000,000 procedures
have been performed in the U.S. alone. Over 3,000,000 treatments have
been performed in the last eight years worldwide.
What is the difference between RK and PRK?
While radial keratotomy (RK) sounds similar to
photorefractive keratectomy (PRK), the two procedures are different and
should not be confused. In RK, a surgeon reshapes the cornea by using a
hand-held blade to make a pattern of incisions in the cornea that look
like the spokes of a wheel. Those incisions cut through more than 90%
of the thickness of the cornea and weaken the structure of the eye.
This weakening permits the cornea to flatten, thus shortening the
length of the eye and correcting the refractive error.
PRK, or Photorefractive Keratectomy, does not include an
incision on the cornea. Instead, an excimer laser carefully shapes or
sculpts the corneal surface by ablating or removing tissue from the
corneal surface. The thickness of tissue removed is often less than
that of a human hair. Laser vision correction with PRK involves the
removal of less than ten percent of the corneal tissue because the
excimer laser is so precise. The end result is a re-sculpting of the
cornea, allowing light to properly focus on the retina. PRK was studied
in clinical trials for six years before approval in the United States.
It uses a computerized laser to correct nearsightedness(myopia) and
What is LASIK?
LASIK (Laser in-situ keratomileusis) also utilizes the
excimer laser to remove corneal tissue in order to reshape the cornea.
With LASIK, the surgeon first creates a flap on the cornea with a
device called a microkeratome. He then uses the excimer laser to
reshape the cornea below the corneal flap. The corneal flap is then
placed back into position and healing begins with good surface
integrity in 12 hours.
What is an Excimer Laser?
A laser is an instrument that can produce and control a
powerful beam of light. Laser light can be directed and controlled more
precisely than normal light, and it can be delivered in extremely
brief, intense pulses. The excimer laser produces a beam of ultraviolet
light in pulses that last only a few billionths of a second. Each pulse
removes a microscopic amount of tissue by evaporating it, producing
very little heat and leaves underlying tissue virtually unchanged.
Is laser vision correction the same as Radial
No. While both treatments are designed to correct
nearsightedness, RK and laser vision correction are not the same. The
revolution in eyecare - changing the shape of the cornea itself - began
with radial keratotomy (RK). Although successful with some types of
nearsightedness, RK is an invasive surgical procedure involving the use
of scalpels to make a series of corneal incisions, cutting into as much
as 95% of the cornea. Laser vision correction uses a state-of-the-art,
computerized excimer laser to reshape the cornea with no incisions.
During the last decade, physicians worldwide have turned increasingly
to laser vision correction and have performed the treatment over one
What can I expect from the laser vision correction
Prior to treatment, the physician administers anesthetic
eyedrops to the patient to numb the cornea. After the eye drops have
had a chance to take effect, the patient is positioned in a comfortable
chair centered underneath the laser and is asked to focus on a small
bright light. Once the laser is properly aligned and the patient feels
comfortable focusing, the actual treatment may begin. Depending upon
the amount of correction required, the laser treatment itself takes
about 15-40 seconds. The patient remains awake throughout the
treatment. The treatment itself is painless, although the patient may
notice a "gritty" sensation in the eye or some discomfort in the first
24-48 hours. Medication may be provided to minimize any discomfort.
Typically, the patient will notice improved vision within 3-5 days and
can usually resume normal activities in 1-3 days. Often patients prefer
to be treated on a Thursday or Friday afternoon to reduce time away
from work. Vision may fluctuate over the next few weeks, and usually
stabilizes within three months.
How do I know whom to trust for this procedure?
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How do I know if I'm a good candidate for laser
A large majority of all nearsighted (myopia) and
farsighted (hyperopia) people are potential candidates for the laser
treatment. Typically, patients who are at least 18-21 years of age who
have mild to high myopia (up to -14 diopters of nearsightedness),
astigmatism (up to 5 diopters of astigmatism), and farsightedness (up
to +6 diopters of farsightedness). The excimer laser is FDA approved
for nearsightedness, astigmatism, and farsightedness with PRK.
Recently, November 1999, the FDA also approved the excimer laser for
LASIK. Patients may be required to meet certain medical and visual
criteria. The best candidates tend to be people who are dissatisfied
with their contact lenses or glasses and are motivated to make a change
, whether it's due to occupational or lifestyle reasons. However, only
an eye doctor who is specially trained in laser vision correction can
evaluate a patient's suitability for the treatment.
How do I know if it's safe?
The excimer laser has proven to be safe and effective
for the treatment of the vast majority of nearsighted and farsighted
prescriptions. In the U.S. clinical trials' three-year follow-up, no
sight-threatening complications have occured. Over 3,000,000 treatments
with the excimer laser have been performed worldwide.
Can I afford the treatment?
There are several ways for you to carefully evaluate
whether or not this treatment will be 'affordable' for you. First,
consider the costs associated with maintaining your eyeglasses or
contact lenses. Depending on the type used some can be costly,
especially when adding in the cost of solutions and other accessories.
While it is harder to place a dollar value on lifestyle, we recommend
that you consider this factor as you assess affordability. Ability to
actively participate in a hobby, sports or your profession without the
aid of glasses or contacts might be very important to you. Most centers
and doctors offer a range of payment options to meet your needs.
What are the risks and side effects that I should
be aware of?
As with any medical procedure, there are risks and
side effects involved. Each patient must understand that a specific
result cannot be guaranteed; however, results can be closely predicted
based on data from thousands of previous cases. Serious complications
are very rare, and the most likely is an infection, which is treatable
with medication. Some possible complications include haze, perforation
of the cornea, induced astigmatism, and under- or over-correction.
However, thousands of refractive procedures have been performed in the
United States, and they are recognized as some of the most successful
and gratifying procedures performed. Since risks and side effects vary
from patient to patient and are very important to consider, your
refractive surgeon will cover these issues with you on a one-to-one