Lasik
Laser
in-situ keratomileuis (Lasik) is a laser refractive procedure in which a portion
of the outermost layer of the eye is temporarily pulled away to allow a laser
beam to make direct contact with the stroma of the cornea. The laser beam is
used to reshape the cornea so that it focuses light properly into the eye. The
outer layer of the eye is then replaced. Recovery time after a Lasik procedure
is usually very short, often a matter of hours, and patient satisfaction with
the procedure is very high. The procedure is nearly painless, and it can be used
to treat myopia, hyperopia, and astigmatism. Lasik was introduced in the mid
1990's, and is now the most commonly performed laser vision correction
procedure.
PRK
Photorefractive keratectomy (PRK) was one of the first laser
refractive surgery procedures performed to correct vision defects. In PRK, the
outermost layer of the eye is removed, and then a laser beam is used to reshape
the cornea. PRK can be used to correct myopia, hyperopia, and astigmatism, and
results are fairly predictable. The removal of the outermost layer of the eye
can result in significant discomfort, long recovery time, and the need for
steroid drops to reduce inflammation in many patients. PRK was introduced in the
early 1990's.
RK
Radial keratotomy (RK) was introduced in the 1980's as a
surgical technique to correct myopia. RK involves surgical scarring of the
peripheral cornea to change the curvature of the cornea. Small incisions are
made at even intervals around the surface of the eye. As the incisions heal,
scar tissue develops and causes the cornea to reflect light at different angles.
RK outcomes are often unpredictable and rely heavily on the individual surgeon
performing the procedure. It also introduces the possibility for serious eye
damage and compromises the integrity of the eye. Since the introduction of the
laser refractive procedures, RK has rarely been performed in the United States.
AK
Astigmatic keratotomy (AK) is a variation of RK that corrects
astigmatism. In AK, incisions are made in the eye at angles instead of at even
intervals. AK, like RK, is rarely performed in the United States due to the
significant potential for complications and the introduction of laser refractive
procedures.
