The cornea is the clear front window of the eye. The cornea focuses light onto the retina, which is at the back of the eye. If the cornea is damaged it may become swollen or scarred. Scars, swelling or an irregular shape cause the cornea to scatter or distort light, which will result in glare or blurred vision. A corneal transplant may be needed when vision cannot be corrected satisfactorily using other procedures, or if painful swelling cannot be relieved by medications or special contact lenses. The following conditions may require corneal transplant: corneal failure after other eye surgery; keratoconus; hereditary corneal failure (Fuch’s); corneal dystrophies; scarring after infections; rejection after the first corneal transplant; or scarring after other eye surgery.
Of all the transplant surgery done today (hearts, lungs, kidneys, etc.) corneal transplants are by far the most common and successful.
Preparing for Surgery
Surgery is usually done with local anesthesia on an outpatient basis. You may be asked to skip breakfast, depending on the time of your surgery. Once you arrive at the operating room, you will be given eye drops and sometimes medications to help you relax.
Before a donor cornea is released for transplant, the eye bank tests the human donor for the viruses that cause hepatitis and AIDS. The cornea is then carefully checked for visual clarity. Your ophthalmologist may request that you have a physical examination and other special tests prior to surgery. If you usually take medications, ask your ophthalmologist if you should continue them.
During Surgery
The operation is painless. Anesthesia is either local or general, depending on your age, medical condition, and eye disease. You will not see the surgery while it is happening, and you will not have to worry about keeping your eye open or closed. After the anesthetic has taken effect, the eyelids are gently opened. Looking through a surgical microscope, your ophthalmologist will measure the eye to determine the size of the corneal transplant. The diseased or injured cornea is carefully removed from the eye. Any necessary additional work within the eye, such as removal of a cataract, is completed. Then the clear donor cornea is sewn into place. When the operation is over, the ophthalmologist will usually place a shield over the eye that has just received the transplanted cornea.
After Surgery
If you are an outpatient, you may go home after a short stay in the recovery area. You should plan to have someone else drive you home.
Follow-Up
Following your surgery, you will need to:
* Use the eye drops as prescribed;
* Be careful not to rub or press on your eye;
* Use over-the-counter pain medicine if necessary;
* Continue normal daily activities and moderate exercise;
* Ask your doctor when you can begin driving;
* Wear eyeglasses or an eye shield if advised by your doctor.
* Several postoperative visits are needed to check on the progress of the eye as it heals.
Potential Risks
Corneal transplants are rejected 5% to 30% of the time, depending on the reason for the transplant. The rejected cornea will cloud and vision will deteriorate. Most rejections, if treated promptly, can be stopped with minimal injury. Warning signs of rejection are persistent discomfort, light sensitivity, redness, or change in vision. Any of these symptoms should be promptly reported to your ophthalmologist.
Other treatable complications can include infection, bleeding, swelling, detachment of the retina, or glaucoma.
A corneal transplant can be repeated, usually with good results, but the overall rejection rates for repeated transplants are slightly higher than for the first transplant. Irregular curvature of the transplanted cornea (astigmatism) may slow the return of vision, but is treatable. Visual recovery takes at least a year after transplant surgery, and your vision may continue to improve up to two years after transplant surgery.
Even if the surgery is successful, any other underlying eye conditions such as macular degeneration, glaucoma, or diabetes (retina damage) may limit vision after surgery. Nevertheless, corneal transplantation may still be worthwhile. No other surgery has so much to offer when the cornea is deeply scarred or swollen.
Never forget that corneal transplant surgery would not be possible without the hundreds of thousands of generous donors and their families who have donated corneal tissue so that others may see!
