PRK ( photorefractive keratectomy) invented in the early 1980’s. The first FDA approval of a laser for PRK was in 1995, but the procedure was practiced in other countries for years. In fact, many Americans had the surgery done in Canada before it was available in the United States.
PRK is performed with an excimer laser, which uses a cool ultraviolet light beam to precisely remove (“ablate”) very tiny bits of tissue from the surface of the cornea in order to reshape it. When you reshape the cornea in the right way, it more precisely focuses light into the eye and onto the retina, providing clearer vision than before.
Both nearsighted and farsighted people can benefit from PRK. With nearsighted people, the goal is to flatten the too-steep cornea; with farsighted people, a steeper cornea is desired. Also, excimer lasers can correct astigmatism, by smoothing an irregular cornea into a more normal shape.
Before treatment, you may be given medication to help you relax. Eye Drops numb your eyes. A device is used to keep your eyes open. An instrument with alcohol solution in it is briefly placed on the cornea. The surgeon then rolls back the softened (“ablated”) epithelium tissue. Laser lasts from 10 to 90 seconds. Bandage Contact lenses are then placed on the eyes to provide comfort during the healing process. For a few days after the procedure, your vision may seem worse. It should begin to improve in about 5-7 days, and become stable in about 4-6 months.
PRK is better for patients with thin corneas, dry eyes, previous glaucoma surgery, mild corneal scars, or other corneal problems.