Corneal Transplants

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Corneal transplants are by far the most common and most successful organ transplants done today. The cornea is the clear “window” in front of the coloured part of the eye. Light is focussed while passing through the cornea so we can see.

If the cornea is damaged or unhealthy it becomes swollen or scarred. Its smoothness and clarity may be lost. Scars, swelling or an irregular shape cause the cornea to scatter or distort light, resulting in glare or blurred vision.

A corneal transplant is needed if:

• Vision cannot be corrected satisfactorily any other way.
• Painful swelling cannot be relieved by medications

WHAT CONDITIONS MAY REQUIRE CORNEAL TRANSPLANTS?

• Keratoconus, a steep curving of the cornea;
• Corneal failure after other eye surgery, such as cataract surgery;
• Hereditary corneal failure, such as Fuch’s dystrophy;
• Scarring after infections or injury
• Rejection of a previous corneal transplant;

BEFORE SURGERY

Once you and your ophthalmologist decide you need a corneal transplant, your name is put on a list at the Lions Corneal Donation Service, which is based at the Royal Victorian Eye and Ear Hospital. Usually the wait is 6-7 months. The cost for the graft material is about $1300, which is reimbursed by private health insurance.

Before a cornea is released for transplant, the Eye Bank tests the human donor for the viruses that cause hepatitis and AIDS using the most accurate and up-to-date tests available. They cannot test for Mad Cow Disease. The cornea is carefully checked for clarity and quality. Although the donor tissue is subject to stringent quality control, responsibility cannot be undertaken for its complete safety.

THE DAY OF SURGERY

Surgery is often done on an outpatient basis. You may be asked to skip breakfast, depending on the time of your surgery. Once you arrive for surgery, you will be given eye drops and sometimes medications to help you relax.

Anaesthesia is either local or general, depending on your age, medical condition and eye disease. The operation is painless. You will not see the surgery while it is happening, and will not have to worry about keeping your eye open or closed.

THE OPERATION

The eyelids are gently held open with a small instrument called a speculum. Looking through a surgical microscope, Dr Sullivan measures the eye for the size for the corneal transplant. The diseased or injured disc of cornea, usually about 8mm in diameter, 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, usually with 16 sutures.

When the operation is over, about an hour after, Dr Sullivan will place a protective shield over your eye.

AFTER SURGERY

If you are an outpatient, you may go home after a short stay in recovery area. You should plan to have someone else drive you home. An examination at the Dr Sullivan’s office is usually scheduled for the following day. Vision is usually very blurry initially, and usually improves slowly over the first few weeks. There is usually some irritation and watering for the first few days. Post operatively some patients may have a small air bubble in the eye for a day or two and may need to rest looking straight up as much as possible. Because the sutures which hold the graft in place cause some distortion of the graft surface there is often visual distortion for some months.

You will need to:

• Use the eye drops as prescribed (normally for 6-9 months);
• Use Panadeine if necessary for pain;
• Avoid eye injury
• Wear eyeglasses or an eye shield as advised by Dr Sullivan.
• Be careful not to rub or press on your eye;
• Continue normal daily activities except vigorous exercise or swimming for 2 weeks;
• Ask Dr Sullivan when you can begin driving again. Usually if vision was poor in the eye before surgery but good in the other eye, patients can drive after a few days.

Dr Sullivan will decide when to remove the sutures, depending upon the health of the eye the rate of healing and the vision. Sometimes sutures will be manipulated or removed after about 1 or 2 months to improve vision. Usually it will be 9 to 18 months before all sutures are removed and before best final vision is obtained. About 8-10 office visits are needed in the first year after operation. Glasses, contact lenses or even further refractive surgery may be needed to get best vision after the corneal graft. The grafted cornea is never as strong again as it previously was, and is prone to rupturing if injured. It is important to protect the eye against injury indefinitely. Even a finger poked into the eye can damage the graft.

WHAT COMPLICATIONS CAN OCCUR?

Possible serious complications include:

• Infection in the eye (endophthalmitis) – 1 in 2,000 cases
• Serious bleeding; 1 in 2,000 cases
• Retinal swelling or detachment; 0.5% of cases (2% in very short sighted people)
• Glaucoma, which may require drops or further surgery for control (10%)
• Transmission of infectious diseases from the donor tissue (including HIV and “mad cow disease”) - extremely unlikely (the donor tissue is checked for HIV and Hepatitis).

Less serious complications include:

• A leaky wound which may need resuturing
• Infection of the graft or sutures
• A pupil which stays large (dilated) after surgery – this is more likely in eyes that have Keratoconus or an increase in pressure at the time of surgery
• Persistent eye irritation
• Double vision

All of these complications may cause vision problems, but can be treated, and some may require further surgery.

Irregular curvature of the transplanted cornea (astigmatism) is common and may slow the return of clear vision, but can be treated with glasses, contact lenses, adjustment of or removal of some of the sutures, or refractive surgery (LASIK or astigmatic incisions in the graft). Vision may continue to improve over the first year after surgery.

Even if the surgery is successful, other eye conditions, such as macular degeneration (ageing of the retina), cataract, glaucoma or diabetic damage, may limit vision after surgery. Even with such problems, corneal transplantation may still be worthwhile.

REJECTION OF THE GRAFT

Corneal transplants are rejected 5% to 10% of the time, and this can occur at any time after surgery. The risk is highest in the first 6 months after surgery and then decreases. The rejected cornea can go cloudy and vision deteriorates. Most rejections, if treated promptly, can be reversed with minimal injury to the graft.

Warning signs of graft rejection are:

• Redness of the eye
• Sensitivity to light
• Visual deterioration.
• Pain or increased discomfort

So: R.S.V.P! if any of these occur.

Any of these symptoms present for more than one day mean you should report to Dr Sullivan or another ophthalmologist, optometrist, or the hospital promptly for treatment.
A corneal transplant can be repeated, usually with good results, but the overall rejection rates for repeated transplants are higher than the first time around.

A recent surgical innovation is called Deep Anterior Lamellar Keratoplasty, where only 99% depth of the patient’s cornea is removed. This means that the graft cannot be rejected. However the average sharpness of vision is less with this technique than with full thickness corneal grafting.

A successful corneal transplant requires care and attention on the part of both the patient and Dr Sullivan. However, no other surgery has so much to offer when the cornea is deeply scarred or swollen. The vast majority of people who undergo corneal transplants are happy with their improved vision. Of course, corneal transplant surgery would not be possible without the thousands of generous donors and their families who have donated corneal tissue so that others may see.

A letter of appreciation from a recipient of a corneal graft will be passed on to a corneal donor’s family by the Lions Corneal Donation Service if submitted.

RECENT SURGICAL INNOVATIONS

DALK
A recent surgical innovation is called Deep Lamellar Keratoplasty, where only 99% depth of the patient’s cornea is removed. This means that the graft cannot be rejected. However the average sharpness of vision is a little less with this technique than with full thickness corneal grafting. It is not always technically feasible to use this technique. Post operatively patients may have a small air bubble in the eye for a day or two and may need to rest looking straight up as much as possible.

DSAEK/DMEK
When endothelial cells are healthy, they pump eye fluid out of the cornea. If the endothelial pump is compromised for any reason the cornea will over-hydrate and become cloudy. This most commonly occurs in patients after complicated cataract surgery or patients who have Fuchs' Endothelial Dystrophy. Vision may eventually deteriorate to a point where these patients feel like they are looking through wax paper. Such patients are good candidates for the DSAEK/DMEK procedure.

DSAEK/DMEK is a new corneal transplant technique where the unhealthy, innermost 1% (the endothelium) of a patient’s cornea is removed and replaced with healthy donor tissue obtained from the eye bank.

Unlike conventional corneal transplant surgery known as penetrating keratoplasty (PK), the DSAEK/DMEK procedure utilises a much smaller surgical incision and requires no corneal sutures. This usually results in more rapid visual rehabilitation for the DSAEK/DMEK patient and also reduces the risk of sight threatening complications that may occur with the PK procedure such as intraoperative expulsive haemorrhage or post operative traumatic wound rupture. The downside to DSAEK/DMEK is that the corneal transplant may not last for as many years as a full thickness surgery. Also patients have an air bubble in the eye for a few days after the surgery and should not fly. They may also need to maintain a supine posture for a day or two. Also there is about a 10% chance of the graft not working at all, or of it falling off in the eye, and the patient and surgeon needing to go back to the OR to reposition the graft. DSAEK/DMEK is usually only recommended for patients that have had their cataracts already operated, as the surgery can cause a cataract in a clear lens.

DSAEK/DMEK is an exciting new improvement in our approach to cloudy corneas. However this is a new and still-developing technique, and we expect ongoing improvement in the results in the future.

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