Photorefractive Keratectomy (PRK)
recently, if you were one of the millions of people with a refractive
error-light rays not focusing precisely on the retina-eyeglasses and contact
lenses were the only options for correcting vision. But with the arrival of
refractive surgery, some people may have their vision corrected through
surgery. Photorefractive keratectomy (PRK) is one of several refractive surgery
procedures used by ophthalmologists to permanently change the shape of the
cornea to improve the way it focuses light on the retina.
is an outpatient procedure, done under topical anesthetic eyedrops. It takes about fifteen minutes. The epithelium,
the outer cell layer of the cornea, is removed with a blade, alcohol or a
laser. An excimer laser, which produces ultraviolet light and emits high-energy
pulses, is used to remove a thin layer of corneal tissue. Your ophthalmologist
enters your vision correction information in a computer and the laser beam
vaporizes the surface of the cornea up to that precise depth. By breaking the
bonds that hold the tissue molecules together, your cornea is reshaped,
correcting the refractive error. Because no incisions are made, the procedure
does not weaken the structure of the cornea.
following surgery the eye is patched or a bandage contact lens is placed on the
eye. After PRK vision is blurry for 3 days to one week. It may take a month or
longer to achieve one's best vision. Patients may be on eyedrops for up to
complications of PRK surgery include undercorrection, overcorrection, poor
night vision and corneal scarring. Permanent vision loss is very rare. In
recent studies monitored by the FDA, 95% of eyes were corrected to 20/40, the
legal limit for driving without corrective lenses in most states.
a candidate for the procedure you must have a stable and appropriate refractive
error, be free of eye disease, be at least eighteen years old and be willing to
accept the potential risks, complications and side effects of PRK.