Understanding Corneal Transplant Surgery

Introduction

Corneal transplant surgery is quite common; some 5,000 transplants are done in the United States every year. In recent years, the chances of success of this operation have risen dramatically because of new advances such as the surgical microscope, finer, less irritating sutures, and better eye banking techniques. In fact, many patients can expect better than a 90% chance of a clear transplant. Even though this surgery is a unique and sometimes frightening experience for you as a patient, we hope that this section will help to guide you through this new experience by answering questions concerning corneal transplant surgery and your role in ensuring its success.

What is the Cornea

Corneal transplant surgery involves removing the diseased cornea surgically and replacing it with a donated cornea. To help you better understand this, let us briefly describe just what the cornea is.
In the healthy eye, the cornea is a clear, dime-sized piece of tissue that fits like a watch crystal over the blue or brown-colored part of the eye called the iris. Light passes through the cornea (just as it would through a window), through the pupil, then through the lens. The cornea and lens focus light rays on the retina in the back of the eye. The retina then transmits the image of sight along nerves to the brain.
The eye is like a camera in which the retina acts as the film and the cornea and lens act like two lenses of the camera. Cloudiness or irregularity of the cornea or of the lens of the eye results in a blurry image, just as a faulty camera lens would result in a poor photograph.
Corneal cloudiness or irregularity can result from many different kinds of diseases, such as infections, injuries, or inherited tendencies towards a cloudy cornea. In addition, the lens of the eye may become cloudy; this is called a cataract. Depending on the problem, a person might need just a new cornea or a new cornea with removal of the cataract.

Light is Scattered by Corneal Clouding or Irregularity

The eye bank receives information regarding the availability of the eye donations, arranges for the collection and distribution of the tissue, and notifies the ophthalmologist with patients listed for surgery that the operation can be scheduled. There is no charge for the donor tissue, but the costs of operating an eye bank are quite high and patients receiving corneal transplants are asked to pay a service fee to help defray expenses.

You might be curious to know something about the donor of your corneal transplant; it is the policy of all eye banks that the donor remains anonymous. Certain general points might be of interest. Donors between the ages of 5 and 75 are considered acceptable if the tissue has been obtained promptly and passes the careful screening procedures. Sex, race, blood type, nearsightedness farsightedness, and eye color are not considered in selecting the donor because they do not affect the outcome of the corneal transplant surgery.

The donated corneas are carefully screened for transmittable disease, including AIDS and hepatitis B. Although there has never been a case of AIDS reported from a transplanted cornea, all donor tissue is screened for AIDS and rejected if positive. Indeed, if any of the known transmittable conditions are suspected by medical history or screening examination, the cornea is rejected and disposed of.

If the surgery is performed under local anesthesia, you will be temporarily put into a light sleep with an intravenous medication; the local anesthesia will then be injected in the area around the eye. In most instances, patients do not feel or even remember this injection. Afterwards, your eye will be totally numb and the surgery can be performed while you are awake, but lightly sedated.

If the surgery is performed under general anesthesia, you will be put to sleep, and a plastic tube will be placed in your windpipe to breathe for you. Again no eye pain will be experienced.

Primary Transplant Failure: Fortunately, this is rare. It occurs in the first week or two after surgery and is caused by a fault in the donor cornea. The only treatment is to do another transplant with a different donor cornea.

Graft Rejection: This is quite unusual. It happens when the body becomes "allergic" to the graft and can occur at any time two weeks or more after surgery. There is a good chance that this can be successfully treated if you act immediately. There are four danger signs that you must know. If any of these occur and last for more than six hours, you should immediately call us. These signs are:

1. Red Eye: It is normal for your eye to be red in the first few weeks after surgery. If, at any time, your eye begins to get redder, then this is cause for concern and you should call your ophthalmologist. You can easily check the redness of your eye by looking into a mirror and pulling down the lower lid. Look carefully at the white part of the eye, especially in the area next to the cornea. You might even check your eye periodically even if you're not having any problems, so that you will know what it looks like when it is normal.
2. Decreased Vision: Even though it can take weeks or months to get good vision after you've had your transplant, your vision probably will be gradually improving after your surgery. Pick an object in your house that has some pattern or detail to it and get in the habit of covering your good eye and looking at this object every day. In this way you can tell how your vision is doing. If your vision seems to be getting worse, there could be a problem with your eye, and should call us.
3. Pain: It is normal to have occasional small twinges of pain in your eye but if your eye develops constant pain for several hours, please call us.
4. Increased sensitivity to light: Bright light might seem very irritating to your eye after surgery. This should slowly get better. If you notice that your eye seems to be getting more sensitive to light and that you feel like squinting or covering it, you should call us.

Wound Separation: This is a break in the area where the edge of the graft is sewn into the eye. There might be no symptoms at all or only a dull ache. It may be treated with a light patch or soft contact lens or it may require a trip back to the operating room so that additional suturing of the transplant can be done.

Astigmatism: This occurs when the transplanted corneas has an oblong shape similar to the surface of a football rather than the round shape of a basketball's surface. All transplants have some amount of astigmatism and usually this can be corrected with glasses or contact lenses. If this astigmatism is severe, a refractive procedure can often correct it.

Loose Suture: This is not uncommon. Sometimes during the healing process sutures can loosen and case a foreign body feeling, especially when you blink. The loose suture can easily be removed in the office.

Postoperative visits are routinely scheduled for the following intervals after your surgery: 1 day, 5-7 days, 3 weeks, and 6 weeks.  This may vary according to your particular circumstances. Subsequent visits are usually at monthly or bimonthly intervals during the first year after surgery.

If you live too far away to have follow-up care with us, and you have no referring ophthalmologist, then we will be happy to work with you to find an ophthalmologist near your home who can provide you with your postoperative care.

Stop taking any medication containing aspirin 7-10 days before surgery. If you are taking a "blood thinner" such as Coumadin, this will need to be stopped a few days before surgery: please check with your doctor for exact instructions. Also, please consult with your doctor concerning when and if you should stop taking any other medications. Bring all medications that you are currently taking when you come for your office visit on the day before surgery.

The suture holding your graft in place is usually allowed to remain in the eye for a year or sometimes longer. When the suture is removed, a substantial change in your eye glasses prescription will occur. This suture can easily and painlessly be removed in the office.