LASIK: Breakthrough Eye Surgery Procedure
LASIK, one of the biggest breakthroughs in eye surgery, is a
surgical procedure that uses non-thermal technology to change
the shape of the cornea in order to improve vision. LASIK, which
is actually an acronym for Laser-Assisted in Situ Keratomileusis
(though few people ever know about it), meaning "reshape the
cornea with laser."
There are other kinds of refractive surgical procedures, but
LASIK is the most advanced. Although LASIK and PRK
(Photorefractive Keratectomy) use the same type of laser, their
procedures are different with the way the stroma, the middle
layer of the cornea is exposed. In PRK, the top layer of the
cornea is scraped to espose the stromal layer while in LASIK,
only a flap is cut in the layer and then folded back.
LASIK involves a two-step procedure. The first step involves the
creation of a micro-thin flap of corneal tissue with the use of
a disposable blade through microkeratome or with a laser,
through IntraLase. Throughout the procedure, a small area of the
eye is left untouched at one end to keep it attached to the eye.
The second step involves the folding back of the flap and using
an excimer laser to treat the corneal tissue. The excimer laser
corrects myopia by flattening the cornea, hyperopia by
steepening the cornea and astigmatism by making the cornea more
symmetrical.
In addition, LASIK also corrects presbyopia, which is a
condition that often occurs with old age. Presbyopia is the
inability of the eye to see things clearly or to focus sharply
on nearby objects. LASIK, however, can only correct one eye for
clear distance vision and the other eye for clear near vision.
This is called monovision.
The Excimer laser, which is the secret behind the procedure was
actually originally developed by IBM for computer chips. The
technology makes use of a cool beam of ultraviolet light,
meaning that most of the heat generated dissipates quickly. This
cooling property makes Excimer laser very ideal for eye surgery
because it can vaporize corneal tissue without damaging the eye
tissue through heat.
And because it is originally developed with computers in mind,
the laser is extremely precise, with an accuracy of 0.25
microns. That is less than one one-thousandth of a millimeter.
For most procedures, one need only to remove or correct 50
microns of thickness, which is as thick as a single human hair.
Aside from it being a safe procedure, LASIK also allows for
rapid visual recovery and little post-operative discomfort
unlike other kinds of surgery. There is also less chance for
corneal haze and scarring as well as fluctuations of vision.
As "perfect" as the procedure may seem, LASIK, like any other
surgeries, can still result in complications and may involve
several risks.
Some temporary conditions that could occur are:
1. Dry eyes 2. Sensitivity to bright lights 3. Glare or streaks
around bright lights
The following conditions are also possible, but very rare:
1. Under-corrections and over-corrections that require an
enhancement, which has about 10 percent risk
2. Wrinkling of the corneal flap that requires repositioning of
the flap, which is really infrequent
3. Permanently blurred vision that may not be corrected by
eyeglasses, contact lenses or any other enhancements; and
infection of the cornea that leads to the scarring and
permanently blurred vision.
Knowing these conditions can happen, it is important that before
a person decides to undergo the procedure, he or she consults
with specialists. Doctors also provide surgical consent that
patients must sign before undergoing any procedure.