Purpose: To evaluate frequency and risk factors of immunologic graft reactions after allogenic penetrating keratoplasty.
Design: Interventional comparative nonrandomized clinical trial.
Methods: The setting took place in a university eye hospital. The retrospective study included 338 patients (338 eyes). The patients underwent penetrating keratoplasty performed by a single surgeon in the study period from 1989 to 1997. Follow-up period had to be longer than 12 months (mean +/- SD, 31.4 +/- 18.8 months). Frequency of immunologic graft reactions characterized by relatively few small monomorph whitish cells in the anterior chamber, almost no flare, and retrocorneal cellular precipitates.
Results: Immunologic graft reactions were detected in 46 patients (46/338 = 13.6%). Statistically significant risk factors for the development of graft reactions were loosening of sutures (P =.046), and preoperative and postoperative corneal vascularization (P =.04). Frequency of an immunologic graft reaction was statistically independent (P >.05) of the graft diameters used in the present study, age, and gender of the patients, HLA-typing, donor age, and preservation data of the donor material. Seventy-four percent (34/46) of all graft reactions were detected within the first 2.5 years after surgery. Thirteen percent (6/46) of all graft reactions were observed more than 4 years after keratoplasty. With intensive corticosteroid treatment, graft transparency could be regained in 44 (95.6%) of the 46 patients with an immunologic graft reaction.
Conclusions: Most important risk factors for immunologic graft reactions occurring in approximately 14% of patients after allogenic penetrating keratoplasty are suture loosening and preoperative and postoperative corneal vascularization. Graft diameters as used in the present study, HLA-typing, age of the donor, and preservation data of the donor material may not play a major role. More than 10% of graft reaction episodes can occur more than 4 years postgrafting. With intensive corticosteroid treatment, graft transparency can be regained in the majority of patients after an immunologic graft reaction when detected early.