Transplant patients were followed intensively during the first months after surgery. The number of clinic visits was tapered to 2 during the third and final year of followup, resulting in a total of 17 postoperative visits. Irreversible failure of the corneal allograft due to all causes was the primary outcome variable in both studies. Allograft reaction episodes, irreversible failure due to rejection, and visual acuity were secondary outcome variables.