Objective: To evaluate the efficacy of oral acyclovir in preventing stromal keratitis or iritis in patients with epithelial keratitis caused by herpes simplex virus (HSV).
Methods: Patients with HSV epithelial keratitis of 1-week or less duration were treated with topical trifluridine and were randomly assigned to receive a 3-week course of oral acyclovir, 400 mg 5 times a day (hereafter referred to as the acyclovir group), or placebo (hereafter referred to as the placebo group). The development of HSV stromal keratitis or iritis was assessed during 12 months of follow-up.
Results: Stromal keratitis or iritis developed in 17 (11%) of the 153 patients in the acyclovir group and in 14 (10%) of the 134 patients in the placebo group. Compared with the placebo group, the adjusted rate ratio for the development of stromal keratitis or iritis in the acyclovir group was 1.16 (95% confidence interval, 0.56-2.43). The development of stromal keratitis or iritis was more frequent in patients with a history of HSV stromal keratitis or iritis than in those without such a history (23% vs 9%; P = .01).
Conclusions: For patients with HSV epithelial keratitis treated with topical trifluridine, no apparent benefit of a 3-week course of oral acyclovir in preventing HSV stromal keratitis or iritis was seen during the subsequent year. The 1-year rate of development of stromal keratitis or iritis was lower than previously reported in the literature, except in patients with a history of HSV stromal keratitis or iritis.