Abstract
Purpose: :
To determine the probability of allograft rejection, recurrent keratoconus, and graft failure, and assess vision-specific quality of life 20 to 25 years after corneal transplantation for keratoconus.
Methods: :
The Michigan Corneal Transplantation Patient Registry files were searched to identify all corneal grafts for keratoconus performed at the University of Michigan from 1980 to 1986. The most recent ophthalmic examination information in their medical record was recorded. An effort was made to contact recipients and request that they return for an ophthalmic examination, and complete the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ) by telephone. Kaplan-Meier survival analysis was used to estimate the time-related probability of allograft rejection, keratoconus recurrence, and graft failure.
Results: :
219 corneal grafts were performed for keratoconus in 184 subjects from 1980 to 1986. Clinical follow-up was available up to 27 years after surgery, with a median follow-up of 10 years. At least one allograft rejection episode occurred in 98 of the 219 grafts. Most rejection episodes took place during the first two years after surgery; at two years, the probability of rejection reached 40% (SE, 3%), but did not increase considerably after that time. Keratoconus recurrence was noted in six grafts, at a range from 9 to 20 years after surgery, with a probability at 20 years of 10% (SE, 4%). 18 grafts (including 3 with recurrence) failed during follow-up, with a 20-year probability of failure of 12% (SE, 3%). 28 subjects, of whom 9 had bilateral grafts, completed the NEI-VFQ at an average time after surgery of 22 years (range, 18 to 26 years). Their mean composite NEI-VFQ score was 84.5 (SD, 12.1).
Conclusions: :
Allograft rejection is a frequent occurrence in the first two years after subjects with keratoconus received a corneal graft. However, the incidence estimates for recurrent keratoconus and graft failure are low, with 20-year estimated probabilities of 10% and 12%, respectively. Given the relative youth of keratoconus graft recipients, these statistics should enhance the information provided preoperatively to them.
Keywords: keratoconus • clinical (human) or epidemiologic studies: outcomes/complications • quality of life