Influential factors and outcome of high-risk keratoplasty in a tertiary referral corneal center – a retrospective study

Abstract Background Corneal allograft survival is decreased in high-risk (HR) host beds. The purpose of this study was to investigate the outcome of HR keratoplasty (KP) in a single-center tertiary referral clinic, and to determine risk factors for graft failure. Methods This retrospective study included adult patients referred for HR penetrating KP between 2014 and 2022. High-risk criteria were history of re-KP, significant stromal neovascularization, and inflammation/perforation at time of surgery. Donor endothelial cell count/age, stromal neovascularization, and perforation/acute inflammation at surgery were independent variables in the logistic regression models for the first year after KP with graft failure as primary endpoint. Results Graft survival 1 year after surgery was 56.2% (CI: 45.7, 66.4), 68.3% (CI: 59.3, 76.4), and 70.2% (CI: 56.6, 81.6) after the first, second, and third KP, respectively. Perforation/acute inflammation at surgery was independently associated with graft failure, which occurred in 190 (51%) of 375 KPs (257 patients). The median time (95% CI) from KP until graft failure was 559 (392, 994), 1052 (833, 1375), and 1089 (689, inf) days for the 1st, 2nd, 3rd KP, respectively. The most frequent cause for failure was immune rejection (29%), with a majority (35%) of graft failures remaining undefined. Conclusions Acute inflammation/perforation at the time of surgery were the major risk factors for graft failure in HR KP. We confirm reduced survival rates for HR KPs, which highlights the persistent need for further developments in individualized treatments in this patient population.