cornea transplantation Cornea Transplantation A cornea transplant involves replacing a diseased or scarred cornea with a new one. When the cornea becomes cloudy, light cannot penetrate the eye to reach the light-sensitive retina. Poor vision or blindness may result. In cornea transplant surgery, the surgeon removes the central portion of the cloudy cornea and replaces it with a clear cornea, usually donated through an eye bank. A trephine, an instrument like a cookie cutter, is used to remove the cloudy cornea. The surgeon places the new cornea in the opening and sews it with a very fine thread. The thread stays in for months or even years until the eye heals properly (removing the thread is quite simple and can be done in the eye doctor's office). Following surgery, eye drops help promote healing and will be needed for several months. Corneal transplants are very common in the United States; about 40,000 are performed each year. The chances of success of this operation have risen dramatically because of technological advances, such as less irritating sutures, or threads, which are often finer than a human hair; and the surgical microscope. Corneal transplantation has restored sight to many people, who only a generation ago would have been blinded permanently by corneal injury, infection, or inherited corneal disease or degeneration. Complications of Corneal Transplant Even with a fairly high success rate, some problems can develop, such as rejection of the new cornea. Warning signs for rejection are decreased vision, increased redness of the eye, increased pain, and increased sensitivity to light. If any of these last for more than six hours, you should immediately call your eye doctor or ophthalmologist. Cornea rejection can be successfully treated if medication is administered at the first sign of bad symptoms. Studies suggest that matching the blood type, but not necessarily the tissue type, of the recipient with that of the cornea donor may improve the success rate of corneal transplants in people at high risk for graft failure. Approximately 20 percent of corneal transplant patients reject their donor corneas. Studies also concluded that intensive steroid treatment after transplant surgery improves the chances for a successful transplant. Cornea transplant Alternatives Phototherapeutic keratectomy laser eye surgery is one of the latest advances in eye care for the treatment of corneal dystrophies, corneal scars, and certain cornea 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 newly smooth surface. Recovery from the procedure takes a matter of days, rather than months as is the case 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, basically 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 Phototherapeutic keratectomy laser eye surgery 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. Phototherapeutic keratectomy laser eye surgery has been approved by the U.S. Food and Drug Administration.