A corneal transplant involves replacing a diseased or scarred cornea with a new one.
It is performed to improve the function of the cornea and improve vision. In corneal transplant surgery, the surgeon removes a portion of the cloudy cornea and replaces it with a clear cornea, donated through an eye bank.
Corneal transplants are very common in the United States, about 40,000 are performed each year. The chances of success for this operation have risen dramatically because of technological advances. Corneal transplantation has restored sight to many, who a generation ago would have been blinded permanently by corneal injury, infection, or inherited disease or degeneration.
Types of Cornea Transplants
The cornea contains five layers. Cornea transplants don’t always transfer all the layers.
Pentrating keratoplasty (full thickness) cornea transplant:
During penetrating keratoplasty, a circular button-shaped, full-thickness section of tissue is removed from the diseased or injured cornea. A matching “button” from the donor tissue is then positioned and stitched into place. This procedure involves transplanting all the layers of the cornea from the donor.
Endothelial keratoplasty cornea transplant:
A newer version of corneal transplant surgery called endothelial keratoplasty is now used for certain corneal conditions. Endothelial keratoplasty replaces only the innermost layer of the cornea and leaves the overlying healthy corneal tissue intact. With this method, the surgeon makes a tiny incision and places a thin disc of donor tissue on the back surface of the cornea. An air bubble is used to position the new layer into place. The small incision is self-sealing and typically no stitches are required. A commonly performed version of this procedure is the Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK).
Endothelial keratoplasty has several advantages over full-thickness penetrating keratoplasty. These include : faster recovery of vision, minimal removal of corneal tissue, no related complications with stitches, and reduced risk of astigmatism after surgery. This procedure has become the preferred technique for patients with Fuchs’ dystrophy and other endothelial disorders of the cornea. However, traditional full-thickness penetrating keratoplasty is still the most appropriate option when the majority of the cornea is diseased or scarred.
Cornea Graft Rejection
The risk of complications vary depending on how many layers of the cornea are transplanted. Complications can be significant and can include cornea graft rejection, eye infection and problems associated with the use of stitches. Rejection of the donor tissue is the most serious complication after a corneal transplant and occurs in 5 to 30 percent of patients. Transplant rejection happens when the body’s immune system detects the donor cornea as a foreign body and attacks and tries to destroy it.
Rejection signs may occur as early as one month or as late as several years after surgery. The surgeon will prescribe medication that can help reverse the rejection process. If detected early, the graft will be successful 90 percent of the time, according to the Cornea Research Foundation of America. Should a graft fail, corneal transplant surgery can be repeated. While repeat surgery generally has good outcomes, overall rejection rates increase with the number of corneal transplants a person has.
Wolfe Eye Clinic has experts in corneal transplant surgery throughout Iowa.
Please contact Wolfe Eye Clinic at 1-800-542-7956 to ask any corneal disease or corneal transplant surgery-related questions or to schedule an appointment with one of our corneal disease specialists: Dr. Steven Johnson, Dr. Todd Gothard or Dr. Matthew Rauen.