Background: Emergency penetrating keratoplasty is said to have a poorer outcome than conventional keratoplasty. We performed a retrospective analysis of 272 cases of emergency keratoplasty to evaluate this hypothesis.
Methods: We analysed 272 cases of emergency keratoplasty and compared the results with a control group of 1,257 scheduled normal-risk keratoplasties and 407 scheduled high-risk keratoplasties. Kaplan-Meier estimations were performed to estimate the percentage of clear graft survival and development of immune reactions. Indications for emergency keratoplasty were microbial diseases (n=109, acanthamoeba, bacteria, fungi), herpes simplex virus infections (n=83), ulcers due to immunological diseases (n=63), and 17 cases of ulcers of unknown origin.
Results: Within 1,500 postoperative days, grafts following emergency keratoplasty suffered statistically significantly more graft failures (clear graft survival, 67.9 vs. 86.9%, P<0.01) and immune reactions (grafts free from immune reactions, 62.8 vs. 78.6%, P<0.01) than grafts following scheduled, normal-risk keratoplasty. There was no statistically significant difference between emergency and scheduled high-risk keratoplasties (clear graft survival, 67.9 vs. 70.2%, and grafts free from immune reactions, 62.8 vs. 66.8%). For emergency keratoplasties, systemic immunosuppression (with cyclosporin A and/or mycophenolatmophetil) had a statistically significant positive effect on clear graft survival (77.4 vs. 63.5%, P=0.01), but not on the development of immune reactions (62.8 vs. 62.3%). A sub-group analysis showed that the effect on clear graft survival was mainly an effect on the underlying systemic immunological disease that had lead to emergency keratoplasty.
Conclusion: This retrospective analysis revealed that clear graft survival is limited following emergency keratoplasty. As in high-risk situations, systemic immunosuppression may be the key to improving prognosis following emergency keratoplasty in the long run.