Introduction
Laser vision correction (LASIK and PRK) is a relatively new procedure used to reduce or eliminate a person's dependence on glasses and contact lenses. The procedure is performed on an outpatient basis and is effective for treating nearsightedness, farsightedness, and astigmatism. To date, over two million procedures have been performed worldwide.
How Does the Laser Work?
The goal of excimer laser LASIK and PRK is to reshape the cornea so that the rays of light that enter the eye are focused clearly onto the retina. The laser produces an ultraviolet beam of light that meticulously removes tissue. Tissue is removed in a precise fashion on a microscopic level, without harming or heating adjacent corneal tissue. This process of tissue removal is called photoablation.
The excimer laser is unique amongst the many types of lasers used in eye surgery. There are three basic categories of medical lasers— thermal (heats tissue), mechanical (cuts tissue), and photochemical (interacts directly with molecules). For example, argon lasers heat tissue and have been used for years to treat disorders such as glaucoma and diabetic eye disease. YAG lasers break tissue bonds by creating a shock wave and are generally used following cataract surgery and to treat certain types of glaucoma. The excimer laser is the only laser properly suited to the task of refractive corneal surgery since it does not heat or mechanically damage tissue. Rather, it directly interacts with chemi...
Copyright 2009 NBC Health
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