What happens during a corneal transplant?

DEAR DOCTOR K:

My eye was severely injured in an accident and I am scheduled to have a corneal transplant. What will happen during this procedure?

DEAR READER:

The cornea is the clear, round “window” of tissue at the front of your eye. Light enters your eye from the cornea, then travels through the pupil and the lens, falling on the retina, the light-sensing part of the eye. A damaged cornea can cause significant vision loss. If this damage is irreversible, a corneal transplant often is the best solution.

In a corneal transplant, your eye surgeon removes the damaged area of cornea and replaces it with a section of healthy cornea. The new cornea comes from a deceased organ donor.

A corneal transplant is usually done as an outpatient procedure. An intravenous (IV) line is placed in your arm to deliver fluids and medications. You are given a sedative and local anesthesia to numb your eye and the surrounding area.

You remain awake during the procedure. Your doctor and nurse will make sure you are comfortable and pain-free. The surgical team uses special techniques to keep your eyes open so you don’t have to worry about blinking.

The eye surgeon will measure your eye to determine the size of the cornea that is needed, and then cut the donor cornea to the right size. The surgeon will remove the damaged cornea, then the donor cornea will be stitched into place using very fine nylon sutures (surgical threads).

Once the transplant is in place, the surgeon may adjust the sutures. Your eye will be covered with a soft eye patch and hard eye shield.

The period right after the surgery and for the next several weeks is critical to the success of the surgery. As your eye heals, you will need to protect your eye, even while you are sleeping. The sutures may be removed after several months or left in place permanently.

Special steroid eyedrops will help prevent your body from rejecting the transplanted cornea. Still, rejection is the most common complication. This happens when the body’s immune system identifies the donor cornea as “foreign” and attacks it. In most cases, this can be treated successfully with medication.

The corneal transplant also can become infected. This, too, is usually successfully treated with medicine.

If there are no donor corneas available, or if several transplants have been rejected, synthetic corneas are available. They are not rejected by the immune system because they are not seen as foreign tissue.

Most people find that their vision improves significantly following a corneal transplant. Expect your vision to improve gradually over a period of months.

There were a few experiments with corneal transplantation in the early 20th century. However, it was in December 1954, at Harvard Medical School, that organ transplantation began in earnest. The remarkable success of organ transplantation is one of medicine’s great achievements over the past half-century.