Influential Factors and Outcome of High-Risk Keratoplasty in a Tertiary Referral Corneal Center: A Retrospective Study

Purpose: Corneal allograft survival is dramatically 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 adults referred for HR penetrating KP between 2014 and 2022. HR criteria were history of re-KP, stromal neovascularization in >= 2 quadrants, and signs of significant inflammation/manifest perforation at the time of surgery. The primary endpoint was graft failure within the first postoperative year. Donor endothelial cell count, donor age, stromal neovascularization, and manifest perforation/acute inflammation at surgery were independent variables in the univariate/multivariable logistic regression. 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. The presence of perforation/acute inflammation at baseline was found to be an independent factor statistically significantly associated with graft failure. Graft failure occurred in 190 (51%) of 375 KPs in 257 patients during overall observation. The median time (95% CI) from KP until graft failure was 559 (392, 994) days for the 1st KP, 1052 (833, 1375) days for the 2nd KP and 1089 (689, inf) for the 3rd KP. The most frequent cause was immune rejection (n=55, 29%), whereas in a majority (n=66, 35%) the reason remained undefined. The median time (95% CI) until neovascularization (re-) formation after KP was 739 days (550, inf) and 1566 (1055, inf) days for the 1st and the 2nd KP. Conclusion: Acute inflammation/perforation at the time of surgery were the major risk factors for graft failure in HR KP. Reduced survival rates for HR KPs were confirmed in this study, which highlights the need for further developments in the treatment of these patients.