A corneal transplant, also known as a corneal graft, keratoplasty or penetrating keratoplasty, involves the replacement of the central portion of a diseased or scarred cornea with a clear, healthy donor.
The cornea is the clear dome shaped window in the front of the eye. Behind this clear window lies the iris, or colored part of the eye. The cornea serves two purposes:
- It forms the front part of the eye’s outer wall and helps to shield the rest of the eye from germs, dust and other harmful matter.
- It is a window allowing the entry of light into the eye. Because of its curvature the cornea functions as a lens focusing incoming light and images onto the retina at the back of the eye.
Although the cornea is clear and seems to lack substance, it is actually a highly organized group of cells and proteins. It measures approximately half an inch in diameter and is thinner than a penny. Unlike most tissue in the body, the cornea contains no blood vessels to nourish or protect it from infection.
Corneal diseases, like keratoconus, can cause clouding, scarring and distortion of the cornea. Replacing the damaged cornea with clear, healthy donor tissue can restore impaired vision.
The doctors at Eye Surgical Associates will help you evaluate your need for a corneal transplant and discuss the potential benefits of the surgery. The final decision is always yours, since you must weigh the potential risks against the possible benefits in making this decision. In some cases when an accident occurs that damages the cornea, the surgery must be done immediately. However, the majority of transplant cases occur because of a diseased cornea. In these cases, the patient has time to gather information, ask questions and decide if this is the best option and if so desired, schedule surgery.
Corneal Transplant Surgery
Corneal transplant surgery is done to improve vision, relieve pain and protect the inner structures of the eye. It is the most successful of all tissue transplants with more than 40,000 corneal transplants being performed in the United States each year. Dr. Catharine Crockett is the corneal specialist at Eye Surgical Associates who performs corneal transplants.
Corneal transplant surgery generally takes about 1 1/2 hours and is performed under a surgical microscope. A cylindrical, cookie-cutter type instrument called a trephine is used to remove a round, button-shaped portion of the diseased or damaged cornea. A “button” of similar size is cut from the donor cornea and placed within the round opening. The donor tissue is then stitched in place with extremely fine nylon sutures.