Corneal Disease (cont.)
IN THIS ARTICLE
Are there alternatives to a corneal transplant?
Phototherapeutic keratectomy (PTK) is one of the latest advances in eye care for the treatment of corneal dystrophies, corneal scars, and certain corneal infections. Only a short time ago, people with these disorders would most likely have needed a corneal transplant. By combining the precision of the excimer laser with the control of a computer, doctors can vaporize microscopically thin layers of diseased corneal tissue and etch away the surface irregularities associated with many corneal dystrophies and scars. Surrounding areas suffer relatively little trauma. New tissue can then grow over the now-smooth surface. Recovery from the procedure takes a matter of days, rather than months as with a transplant. The return of vision can occur rapidly, especially if the cause of the problem is confined to the top layer of the cornea. Studies have shown close to an 85 percent success rate in corneal repair using PTK for well-selected patients.
The Excimer Laser
One of the technologies developed to treat corneal disease is the excimer laser. This device emits pulses of ultraviolet light--a laser beam--to etch away surface irregularities of corneal tissue. Because of the laser's precision, damage to healthy, adjoining tissue is reduced or eliminated.
The PTK procedure is especially useful for people with inherited disorders, whose scars or other corneal opacities limit vision by blocking the way images form on the retina. PTK has been approved by the U.S. Food and Drug Administration.