Allograft rejection after penetrating keratoplasty for keratoconus

We retrospectively studied 91 penetrating keratoplasties in 65 patients to evaluate the overall incidence of allograft rejection and the incidence in unilateral as compared with bilateral cases following penetrating keratoplasty for keratoconus. All surgeries were performed by the senior author following a standardized technique. The average age of the patients was 35 years; the average follow up, 6.5 years. Nine of the 91 grafts (9.9%) were rejected. The time of rejection varied from 6 months to 13 years after surgery. Eight of the nine rejections (88.9%) were reversible with steroid treatment and have survived up to 10 years. One graft failure requiring repeat penetrating keratoplasty (1.1%) occurred 13.25 years after surgery. The unrejected clear grafts have survived up to 21.5 years. The results of this study support the excellent prognosis of penetrating keratoplasty for keratoconus.