Go Back Thailand Medical Procedures
Photo Refractive Keratectomy "PRK"
Photo Refractive Keratectomy, or PRK for short, treatment is carried out as an outpatient procedure. This technic was once very popular due to its effectiveness in treating myopia, hyperopia and astigmatism.The technique is very similar to LASIK, but the keratectomy by microkeratome is unnecessary. The surgoen will gently remove the outer layer of cells (skin) from the surface of your cornea with a hand-held instrument before treating your eye with the laser. You will hear the laser make a faint clicking sound. The whole process takes less than 15 minutes and the laser treatment itself is very brief – typically lasting for no more than 45 seconds. It is a more desirable method for patients with a thin cornea.
The recovery time of PRK is longer than LASIK and there is a greater risk of infection of corneal haze. Steroid eye drops must used for a longer time and close observation and checkups are required.
PRK was invented in the early '80s. 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 U.S.
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 works better to focus 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.