Microbial keratitis and clinical outcomes following penetrating and endothelial keratoplasty

AbstractPurposeThe goal of this study was to review the incidence, risk factors and outcomes of microbial keratitis after penetrating keratoplasty (PK) and endothelial keratoplasty (EK).MethodsThe electronic medical records at Wills Eye Hospital were queried for cases of microbial keratitis following PK or EK performed between 1 May 2007 and 1 September 2018. Charts were reviewed to obtain demographic data, transplant characteristics, details of microbial keratitis, graft survival and clinical outcomes.ResultsDuring the study period, 2098 transplants were performed in 1601 patients. Of these, 1267 (60.4%) were PKs and 831 (39.6%) were EKs. We identified 86 (4.1%) cases of subsequent microbial keratitis. The incidence of microbial keratitis after PK was significantly higher than after EK (5.9% versus 1.3%; p = 0.005). Furthermore, the rate of infection was higher after repeat transplants (either PK or EK) compared to initial keratoplasties (5.5% versus 3.4%; p = 0.02). Twenty‐six (32.1%) grafts remained clear at most recent follow‐up after microbial keratitis, and the proportion of clear grafts was higher after EK than PK (66.7% versus 27.8%; p = 0.03).ConclusionRates of microbial keratitis were significantly higher after PK compared to EK, and repeat transplantation was a risk factor for microbial keratitis. To the best of our knowledge, there is no prior study in the literature evaluating microbial keratitis rates after PK and EK and comparing outcomes.