What does a Corneal Transplant Involve?
Corneal injuries or diseases can leave behind scars, blurring vision and causing other problems (See Figure 1a). The Cornea Associates of Texas surgeons are skilled in performing corneal transplants, a highly successful and common yet intricate surgery designed to restore vision to patients whose corneas have been damaged. During the procedure, the cornea is replaced with a healthy cornea, using human donor tissue (See Figure 1b). More than 45,000 corneal transplants are performed annually in the United States alone. The success of the procedure depends on the underlying corneal disorder; but for the most common conditions, the success rate for surgery is an outstanding 95%, with most patients achieving 20/20 vision or better with correction.
The surgery is performed on an outpatient basis, meaning that patients do not have to spend the night in a hospital. Local anesthesia is used to numb the eye and control eye movement. Appropriate sedation is provided to relieve patients of anxiety associated with surgery. There is little if any discomfort associated with the procedure, and patients are back to work and routine activities often within days following surgery.
The procedure involves removing a circle of tissue (about 8 mm in diameter) from the patient's cornea. This is performed with special microsurgical instruments. A donor tissue is prepared by removing a matching circle of corneal tissue from the donated cornea. The new cornea is secured to the patient's eye with delicate sutures, which are barely visible and rarely irritate the eye.
These sutures hold the tissue in place while the wound heals, which is a slow process. Additional surgery may be performed at the time of corneal transplantation to remove a cataract, replace an intraocular lens implant, control glaucoma or repair the retina. During the first few weeks after surgery, the vision is usually blurred but progressively begins to clear. After two to three months of healing, some of the sutures may be removed and spectacles may be prescribed to focus the vision. However, it may take six months or more before the full recovery of vision has been achieved.
The donor tissue is provided by an eye bank, which carefully screens the tissue. Federal regulations require eye banks to screen all tissue for HIV, hepatitis, and a variety of other diseases. Only healthy tissue, which is free of disease, may be used for transplant surgery. The Eye Bank Association of America provides training and certification of eye banks and supports physician education and research activities. Lions Club International provides funding and support for many local eye banks. A national collaborative effort has made corneal transplantation so successful. Because of the availability of corneal tissue, surgery can be scheduled as an elective procedure at a time convenient for the patient and surgeon.
As with any type of surgery, there are risks associated with corneal transplant surgery. The most important risk is rejection of the transplant. Fortunately, the risk of rejection is small (5% to 10% for most conditions requiring transplantation). The rejection cannot develop during the first two months after surgery; however, it may occur at any time thereafter, even years later. The rejection involves the patient's body becoming sensitized to the foreign corneal tissue and attacking the donor cornea with inflammation. The symptoms of potential rejection can be grouped by the mnemonic RSVP:
R: Redness (unusual redness of the eye)
S: Sensitivity (increase in light sensitivity)
V: Vision (sudden change in vision clarity)
P: Pain (increase in eye pain)
If a rejection of the transplant is developing, the patient should contact the surgeon immediately. The treatment of a rejection involves the use of cortisone eye drops, which is usually successful in reversing the rejection and stabilizing the cornea. However, the treatment must be instituted as soon as possible. If too much time has elapsed for the rejection episode or if the rejection is particularly severe, the cornea may become cloudy and the vision will remain blurred. If the transplant is rejected, surgery may be repeated and also has a high success rate for restoring sight.
Why Choose Us
The surgeons at Cornea Associates of Texas are board-certified and have received cornea fellowship training. We are specifically trained to perform corneal transplant surgery and have over fifty years of experience in this area. We perform about 900 transplant procedures each year, but we carefully evaluate each patient individually during an initial consultation before we recommend the procedure. We also offer extensive pre- and post-operative counseling for our patients.
For more information about corneal transplant surgery or to schedule a consultation, please call our office today.