What is corneal transplantation?
The cornea is the central part of the front of the eye through which we see. Normally, the cornea is smooth and clear. However, injury, disease or certain medical conditions can make it cloudy or difficult to see through. Sometimes this problem can be fixed by removing some or all of the cornea and replacing it with corneal tissue from an organ donor. This operation is called corneal transplantation.
About 46,000 corneal transplantations are performed in the United States every year, according to the Eye Bank Association of America. Information about becoming an corneal donor is available on the association's Web site: http://www.restoresight.org/.
Is it safe to receive donated corneal tissue?
Yes. The medical history of every organ donor is reviewed carefully, and blood tests are performed to check for infections prior to corneal transplantation. If there is any doubt about the safety of corneal transplantation, the donated tissues are used for medical research instead of being transplanted into a patient's eye.
Why do people need a corneal transplantation?
A doctor can recommend corneal transplantation only after a careful examination of the eye. The most common reasons for performing the operation are:
- Injury to the eye — Sometimes an injury will damage the cornea so severely that it will not heal correctly. The cornea plays an important role in vision, so even a small injury to it can greatly reduce vision. The doctor might recommend a corneal transplant to improve vision or, in more serious injuries, a transplant might be the only way to close the wound in the eye.
- Medical conditions — Some infections of the eye can cause damage to the cornea that will not heal. There are also certain medical conditions that make the cornea very thin or cloudy, or cause other problems that can only be treated by replacing the cornea.
- Pseudophakic bullous keratopathy — Some people experience corneal swelling and clouding after cataract surgery. This is known as pseudophakic bullous keratopathy and is a common reason for corneal transplantation.
- Keratoconus — Sometimes the cornea is thin and weak, and the normal pressure inside the eye makes the cornea bulge outward in a cone shape. This is called keratoconus, and it causes severe vision problems. If these problems are very troublesome, the doctor might recommend a corneal transplant. More information is available in the Keratoconus fact sheet available from the Cole Eye Institute.
What happens in a corneal transplantation operation?
Corneal transplantation can be done under general anesthesia; that is, with the patient “asleep.” Local anesthetic, in which the patient is awake but does not feel the procedure, also can be used.
A portion of the cornea is removed using scissors and a special instrument called a trephine, which works something like a tiny circular cookie-cutter. This leaves an opening in the patient's cornea.
A similarly sized trephine is used to cut a section from the donor cornea. This section of corneal tissue is placed into the opening in the patient's cornea and fastened with very small stitches. Many patients qualify for a partial-thickness corneal transplant procedure called DSAEK (Descemet stripping with automated endothelial keratoplasty) tailored to particular corneal disorders. This procedure can provide faster recovery with less visual distortion.
After surgery, it is important not to put any pressure on the eye. It is best not even to touch or rub anywhere near the eye, so the doctor might put a shield over it. Wearing glasses or sunglasses will also help protect the eye.
Your doctor will prescribe eye drops to help the eye heal and prevent infection. It is necessary to keep using some of these medications for several months after a corneal transplant. Without these medications, the eye is much more likely to have problems with the new corneal tissue.
How successful is corneal transplantation?
The majority of the corneal transplantations done in patients with keratoconus, corneal scars and most types of corneal disease are successful. The operation is less successful in eyes with a corneal infection or severe injury such as a chemical burn. In a small number of cases, the new corneal tissue is rejected by the body even though the operation was successful and all medications were taken correctly.
The best way to avoid problems after corneal transplantation is to follow all of your doctor's advice, including using all medications as recommended and keeping all follow-up appointments. At these appointments, the doctor will check your vision in the eye with the transplant. It is not unusual for that eye to have vision that is very different from the other eye. This difference can be very disturbing, but eyeglasses or contact lenses can improve the situation. Vision can change rapidly after corneal transplantation, so it is necessary to visit the eye doctor more often than usual.
Make an appointment now. Or call 216.444.2020 or 800.223.2273 Ext. 4-2020 to schedule an appointment with a Cole Eye Institute ophthalmologist.