Cornea Transplant Surgery
A cornea transplant is a surgical procedure to replace part of your cornea with corneal tissue from a donor. Your cornea is the transparent, dome-shaped surface of your eye that accounts for a large part of your eye's focusing power. A cornea transplant, also called keratoplasty, is an outpatient procedure that can restore vision, reduce pain and improve the appearance of a damaged or diseased cornea. Cornea transplants are the most common transplant operation performed in the United States with about 40,000 performed each year, according to the Eye Bank Association of America.
Many patients can now benefit from a newer transplant technique to replace only the inner layer of the cornea. This corneal transplant procedure is known as DSEK or endothelial keratoplasty. Nearly 70% of all patients needing a transplant can benefit from DSEK. Advantages to DSEK include a more rapid return of clearer vision. No sutures in the transplanted tissue allow for a more secure healing process and less astigmatism.
A number of conditions can be treated with a cornea transplant, including:
Cornea transplant is a relatively safe procedure. Still, a cornea transplant does carry a small risk of serious complications, such as:
Are You a Cornea Transplant Candidate?
Corneal transplants are performed in order to protect the eye's inner structures, relieve pain and improve vision. With these factors in mind, you should consider several important questions before undergoing a corneal transplant:
All of these questions, in conjunction with thorough discussions and screenings with your eye doctor, must be considered before you make the decision to have a corneal transplant.
During Your Cornea Transplant
We have a very sophisticated eye bank system in the United States. Before donor corneas are released for transplant, the tissue is checked for clarity. Also, donor eyes supplying transplant tissue are meticulously screened for presence of diseases such as hepatitis and AIDS or other damage to ensure the health and safety of the recipient.
Typically, corneal transplants are performed on an outpatient basis, meaning that you will not need hospitalization. Local anesthesia supplemented with medication to ensure comfort is preferred. With local anesthesia, an injection into the skin around your eye is used to relax muscles that control blinking and eye movement, and eye drops are used to numb the eye itself. After the anesthesia has taken effect, you will not feel discomfort or the need to keep your eye open.
Full Thickness Transplant (PK)
During a full thickness cornea transplant (penetrating keratoplasty), your surgeon cuts through the entire thickness of the abnormal or diseased cornea to remove a small button-sized disc of corneal tissue. An instrument that acts like a cookie cutter (trephine) makes this precise circular cut. The donor cornea, cut to fit, is placed in the opening. Your surgeon then uses a fine thread to stitch the new cornea into place. The stitches may be removed at a later visit when you see your eye doctor. Finally, the surgeon will place a plastic shield over your eye to protect it from being inadvertently rubbed or bumped. The surgery usually takes less than one hour.
Partial Thickness Transplant (DSEK)
With many types of cornea problems, a partial-thickness transplant is a better treatment option than penetrating keratoplasty. This procedure, endothelial keratoplasty or DSEK, replaces only the innermost membrane of your cornea's five layers. A small incision is made at the edge of the cornea to allow for removal of your cornea's inner membrane without damaging the outer layers. A donor graft replaces the removed portion through the small incision. The transplanted tissue is initially held in place with an air bubble inside the eye. The air dissolves over two to three days as the transplant heals in place without sutures. This surgery also usually takes less than one hour.
After your cornea transplant
Once your cornea transplant is completed, you can expect to:
Most people who receive a cornea transplant will have their vision at least partially restored, but what you can expect after your cornea transplant depends on the reason for your surgery and your health conditions.
Your risk of complications and cornea rejection continues for years after your cornea transplant. For this reason, expect to see your eye doctor once or twice a year after healing has stabilized. Cornea rejection can often be managed with medications.
Most corneal transplants are successful. Nevertheless, recognizing the warning signs of problems is the best way to prevent corneal transplant rejection. Familiarize yourself with the four main signs.
Rejection signs may occur as early as one month or as late as several years after surgery. If you have complications with your corneal transplant, your eye doctor will prescribe medication that can reverse the rejection process. Should your graft fail, the corneal transplant can be repeated, generally with good results. Still, overall rejection rates increase with the number of corneal transplants you have.
Recovering From a Cornea Transplant
The total recovery time for a full thickness corneal transplant (PK) can be up to a year or longer. For DSEK recovery is generally 3 or 4 months. Initially, your vision will be blurry and the corneal transplant may be swollen and slightly thicker than the rest of your cornea. As your vision improves, you will gradually be able to return to your normal daily activities.
For the first several weeks, heavy exercise and lifting are prohibited. However, you should be able to return to work five to seven days after surgery, depending on your job. Steroid eye drops will be prescribed to help your body accept the new corneal graft. You should keep your eye protected at all times so that nothing inadvertently bumps your eye.
Stitches in full thickness corneal transplants may be removed 12 to 24 months after surgery, depending on the health of your eye and the rate of healing. Adjustments can be made to the sutures surrounding the new cornea to help reduce the amount of astigmatism resulting from normal healing around the transplant.
Sight After a Cornea Transplant
Your vision typically will continue to improve in the first one to two years following your surgery. But you will need vision correction (glasses or contact lenses) for nearsightedness and astigmatism, because the curve of the corneal transplant cannot match exactly the curve of your existing cornea.
Because your vision will fluctuate during the year following full thickness transplant surgery, it is typical to wait for that time period or until some of your sutures have been removed to fill an eyeglass prescription and be fitted for contact lenses. Typically this time for visual rehabilitation is much shorter, only 3 to 4 months, for endothelial keratoplasty (DSEK).