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Corneal Transplantation definition
Donor corneas are harvested within a few hours of death and can be preserved for up to 14 days. Current practice does not employ blood type or tissue type matching for corneal transplantation, though some studies suggest matching the blood type of donor and recipient reduces the risk for rejection.
Nearly anyone can donate his or her corneas after death. There is no cost to the donor. An eye bank coordinates the harvesting, testing, storage, and dispensing of donated corneas. Many states incorporate organ donor authorization with driver’s licenses. People should tell family members that they wish to donate their corneas.
Corneal transplantation surgery takes place with a local anesthetic to numb the eye and an intravenous sedative medication for relaxation and comfort. The operation takes 45 to 60 minutes. From the donor cornea, the ophthalmologist uses a trephine, a device that cleanly punches out a buttonlike segment of the cornea’s center. Using a surgical microscope, the ophthalmologist then removes a similarly shaped segment from the diseased cornea and places the donor button in its place.
Very fine suture, sometimes thinner than a human hair, secures the donor corneal button in position and remains in the eye for three months to one year. The ophthalmologist often removes the sutures a few at a time as HEALING progresses, using an ophthalmic anesthetic to numb the affected eye, depending on the rate of vision improvement. Some sutures may remain in place indefinitely.
Corneal Transplantation Recovery
Full recovery typically takes about a year. Some people will have ASTIGMATISM and require CORRECTIVE LENSES following corneal transplantation, resulting from irregularities in the shape of the cornea that develop during healing. Corneal transplantation may correct another VISION IMPAIRMENTsuch as HYPEROPIA (farsightedness) or MYOPIA (nearsightedness) because the OPERATION changes the shape of the cornea.
Complication of Corneal Transplantation
The most common complication of corneal transplantation is rejection of the transplanted cornea, which occurs overall in about 15 percent of corneal transplantations. Rejection is most likely to take place in the first two years after the operation. Early detection and prompt treatment with ophthalmic CORTICOSTEROID MEDICATIONS can reverse the rejection process. Signs of rejection include
Other complications that can occur include INFECTION and bleeding within the eye.