Also known as keratoplasty. If the cornea (see EYE) becomes damaged or diseased and vision is impaired, it can be removed and replaced by a corneal graft. The graft is taken from the cornea of a human donor. Some of the indications for corneal grafting include keratoconus (conical-shaped cornea), corneal dystrophies, severe corneal scarring following HERPES SIMPLEX, and alkali burns or other injury. Because the graft is a foreign protein, there is a danger that the recipient's immune system may set up a reaction causing rejection of the graft. Rejection results in OEDEMA of the graft with subsequent poor vision. Once a corneal graft has been taken from a donor, it should be used as quickly as possible. Corneas can be stored for days in tissue-culture medium at low temperature. A small number of grafts are autografts in which a patient's cornea is repositioned.

(See also DONORS; TRANSPLANTATION.)