Photorefractive keratectomy, or PRK, is a type of laser eye surgery used to correct mild to moderate nearsightedness, farsightedness, and/or astigmatism. All laser vision correction surgeries work by reshaping the cornea, or clear front part of the eye, so that light traveling through it is properly focused onto the retina located in the back of the eye.
There are a number of different surgical techniques used to reshape the cornea. During PRK, an eye surgeon uses a laser to reshape the cornea. This laser, which delivers a cool pulsing beam of ultraviolet light, is used on the surface of the cornea, not underneath the cornea, as in LASIK.
Ideal PRK Candidate
- Wants to reduce or eliminate dependence on glasses or contacts
- Is over 18 years of age
- Has had a stable eye prescription for at least one year
- Has corneas too thin for LASIK
- Does not have dry eyes, cataracts, and degenerative or autoimmune disease
How effective is PRK
Most people achieve 20/20 or better vision after PRK. Studies have shown that 95 to 98 percent of people who undergo PRK are able to drive legally without the use of corrective lenses.
Is PRK painful?
The surgery is virtually painless and is performed using anesthetic eye drops. Following the surgery, pain medication will relieve any eye soreness. Most patients are comfortable within three days.
What is the difference between LASIK and PRK?
Both procedures use a cool-beam excimer laser to reshape the cornea and correct nearsightedness and farsightedness. During PRK, the laser is used to reshape the cornea on top of the actual surface of the cornea. During LASIK, the laser is used to reshape the cornea after a protective flap of tissue is created and lifted. After a thorough eye examination, your doctor will recommend the procedure that he or she feels will give you the best visual results.
What are the risks of PRK?
PRK is among the safest eye procedures performed, though any surgical procedure carries some risk. Some patients may experience temporary light sensitivity, glare or starburst effects around headlights and other bright lights in the evening hours. There may also be some fluctuation of vision during the stabilization period, but in most instances, this subsides within six months following surgery. The risk of infections and scarring is very low.
What to Expect on Surgery Day
Most people don’t feel pain during PRK. First, the eye is numbed using eye drop anesthesia. Then the physician removes a thin, protective layer of tissue that covers the cornea, called the epithelia. During the procedure, the physician will instruct the patient to look directly at the laser’s target light. Then, the excimer laser produces a beam of cool light that lasts only a few billionths of a second, reshaping the surface of the cornea. After the cornea is reshaped, the epithelia are allowed to grow back, which typically takes three to five days. A contact lens will be placed on the eye for comfort and is removed at one week.