Factors associated with graft rejection after penetrating keratoplasty in mechanical corneal injury

Purpose To investigate factors associated with graft rejection after penetrating keratoplasty in patients with mechanical corneal injury and evaluate their predictive value. Methods This retrospective study included 50 patients with mechanical corneal injury who underwent penetrating keratoplasty between 2019 and 2025. Clinical variables, including onset duration, preoperative treatment, and corneal pathological changes, were analyzed. Univariate and multivariable logistic regression, time-to-event analysis, stratified analysis, mediation analysis, and receiver operating characteristic curve analysis were performed. Results Prolonged onset duration and preoperative corneal ulceration were associated with an increased risk of postoperative graft rejection, whereas preoperative treatment was associated with a reduced risk. With increasing onset duration, corneal neovascularization and fibrosis increased, whereas corneal edema decreased. Mediation analysis showed that these associations were mainly driven by direct effects. Prediction models demonstrated good discriminatory performance. Conclusions Prolonged onset duration and preoperative corneal ulceration may be risk factors for postoperative graft rejection in patients with mechanical corneal injury undergoing corneal transplantation, whereas preoperative treatment may be protective. Therefore, early intervention and disease course control are of great importance for improving transplant prognosis. These findings may provide a reference for preoperative risk stratification and perioperative management.