Other Surgical Options
PRK (Photo-Refractive Keratectomy) is also a
surgical procedure to correct visual anomalies such as nearsightedness,
farsightedness, and astigmatism. PRK differs from LASIK in that no flap
is created before applying the laser. The top skin of the cornea, the
epithelium, is brushed away manually before the laser reshapes the cornea. A
"band-aid" contact lens is placed on the eye to protect it as
the epithelial top layer grows back. There is more discomfort with PRK due to
the longer healing time. The vision will be blurry for several weeks before it begins
to clear up. Because of this, sometimes one eye is done at a time to allow
good vision to return in the one eye before doing the other. There is
also a more significant risk for corneal haze or scarring in the visual axis
than with IntraLASIK. As a result, PRK is only performed infrequently
today.
LASEK (Laser Assisted Epithelial Keratomileusis) is
somewhat like a hybrid of LASIK and PRK. LASEK is a refractive surgical
procedure that is performed currently on an investigational basis to correct nearsightedness,
farsightedness and astigmatism. LASEK is much like traditional LASIK in
that a flap is created with a metal blade before reshaping the underlying
corneal tissue. With LASEK, the flap that is created consists only of the
epithelial layer, which is the top layer of cells on the cornea. As a
result, the flap made is far thinner than the stromal (deeper layer) flap that
is created in LASIK.
There are some advantages of LASEK over traditional
microkeratome LASIK. One is that there is no possibility of epithelial
ingrowth (a condition in which the top layer cells known as epithelial cells
can grow underneath the flap). The other is that there is no risk of flap
complications like a partial flap or buttonhole flap because no stromal flap
has been created. However, these latter complications are extraordinarily
rare when the Intralase is used to perform LASIK. As a result, LASEK has
few if any advantages over IntraLASIK.
A significant disadvantage of LASEK is that the
alcohol solution that is placed on the eye to create the epithelial flap is
very harsh and can disrupt the tissue to the point where it cannot be laid down
smoothly. As a result, with LASEK there is frequently much more
discomfort and and very increased healing time when compared to
IntraLASIK. This change in the healing pattern also has the effect of
decreasing the predictability of attaining the right visual correction.
There is also a greater chance of permanent corneal haze with LASEK. This
is a condition in which there is a trace amount of scarring of the
cornea. Because of the delayed healing, it takes several weeks longer for
the vision to improve as compared with IntraLASIK.
The majority of surgeons currently believe that the
few advantages that LASEK offers do not outweigh its disadvantages at this
time. As a result, IntraLASIK remains the safest and most predictable
vision correction procedure available anywhere.
