Long-term Acyclovir Use to Prevent Recurrent Ocular Herpes Simplex Virus Infection

To evaluate the effectiveness of more than 12 months of oral acyclovir therapy in reducing recurrences of ocular herpes simplex virus.We retrospectively compared ocular herpes simplex virus recurrence in 2 groups of patients. In group 1, patients used oral acyclovir for at least 12 months and then discontinued the treatment. In group 2, patients received the treatment for at least 18 months. We compared recurrences when both groups were using acyclovir (period 1) and when only group 2 was receiving the drug (period 2). Statistical analysis was performed with the t test, chi2 test, and Kaplan-Meier method.Group 1 had 18 patients and a mean +/- SD follow-up of 45.2 +/- 22.2 months. Group 2 had 22 patients and a mean +/- SD follow-up of 42.4 +/- 30.2 months. Six patients (33%) in group 1 and 4 patients (18%) in group 2 had recurrence in period 1 (P =.3). In period 2, 14 patients (78%) in group 1 and 8 patients (36%) in group 2 had recurrence (P =.01). Mean +/- SD recurrence-free survival in period 2 was 15.3 +/- 5.5 months in group 1 and 37.3 +/- 6.3 months in group 2 (P =.001).Long-term oral acyclovir use seems to remain effective in decreasing the number of ocular herpes simplex virus recurrences beyond 12 months.