Antiviral treatment following penetrating keratoplasty for herpetic keratitis

Purpose To assess the effect of antiviral treatment on corneal graft survival following penetrating keratoplasty for herpetic keratitis. Methods Retrospective cohort study of 454 patients receiving primary penetrating keratoplasties (PKs) for viral infection reported to NHS Blood and Transplant (NHSBT) between April 1999 and June 2005. Follow-up data were available on 403 PKs. Kaplan-Meier survival estimates were used to determine graft survival for the three treatment groups: no medication, topical antiviral, and oral antiviral medication. A Cox regression model was used to investigate the combined effects of all additional factors on graft failure. The model was fitted using all pre-operative factors first and then postoperative factors including type of antiviral medication were included. Results Patients who received oral antiviral medication post-operatively had consistently better graft survival than those receiving no medication or only topical medication. Patients receiving oral antivirals were less than a third as likely to have a failed graft at 5 years compared with those on no antiviral medication (relative risk (RR) 0.3, CI: 0.2-0.7, P = 0.002). Other factors that were found to influence the risk of graft failure were the presence of deep corneal vascularisation (P = 0.009), PK performed for therapeutic reasons (P = 0.03), large diameter grafts (P = 0.04), and experiencing a rejection episode (P = 0.003). Conclusion Oral antiviral treatment reduces the risk of graft failure in patients undergoing primary PK for herpetic keratitis and should be routinely used in this group of patients post-operatively unless contra-indicated. Eye (2011) 25, 470-474; doi:10.1038/eye.2010.237; published online 28 January 2011