Risk Factors for Corneal Graft Rejection after Penetrating Keratoplasty for Keratoconus

Abstract

Purpose To evaluate the association between donor-related factors and the risk of rejection in patients undergoing penetrating keratoplasty (PKP) for keratoconus. Methods A Retrospective review was performed of keratoconus patients with no corneal neovascularization who underwent PKP from November 2014 to December 2016 and completed at least two years of follow-up. Preoperative, donor, operative, and postoperative data were collected and analyzed to identify factors leading to corneal graft rejection. Results Among the 201 patients (201 eyes) who underwent PKP, 46 patients (22.9%) had an episode of graft rejection. The graft survival rate was 98.5%. Grafts with a death-to-excision time (DET) greater than 8 hours had a 0.53X lower risk of rejection compared with grafts with DET within 8 hours or less (P = 0.05). Rejection was higher in patients receiving grafts with a preservation time within 7 days or less compared with preservation time greater than 7 days (30.6% vs. 21.2%, respectively, P = 0.291). The rejection rate was higher in patients with a history of corneal transplant in the fellow eye than those without keratoplasty in either eye (32.7% vs. 19.2%, respectively; P = 0.077). Graft rejection was 2.4 times higher if recipients developed postoperative stromal neovascularization (P = 0.003). Conclusion Short DET could be an independent risk factor for rejection after PKP. There were no strong correlations between graft rejection and donor age, donor/recipient gender, or graft size.