Prior Contralateral Penetrating Keratoplasty Is a Risk Factor for Second Eye Graft Rejection

To determine whether prior penetrating keratoplasty (PK) in the contralateral eye increases risk of second eye PK graft rejection.Cohort study of 593 consecutive PKs in transplant-naïve eyes (500 unilateral cases, 93 second eyes). Outcomes were compared between PKs performed in eyes with versus without a history of prior contralateral eye PK. Risks of rejection and failure were estimated using Cox proportional hazards models.Mean age was 53.7 ± 23.3 years; average follow-up was 4.00 ± 2.87 years. Rejection occurred in 211 (35.6%) grafts. The incidence of rejection was 34.0% in unilateral cases and 44.1% in second eyes with PK in the contralateral eye. Prior contralateral PK was a significant risk factor for graft rejection (HR = 1.42, 95% CI 1.01-2.01, p = .045).Contralateral PK is associated with increased risk of second eye graft rejection. Loss of ocular immune privilege is a possible mechanism.