Oral acyclovir for herpes simplex virus eye disease - Effect on preventionof epithelial keratitis and stromal keratitis

Objectives: To investigate the effect of oral acyclovir therapy for recurre nces of herpes simplex virus (HSV) epithelial keratitis and stromal keratit is and to determine if certain patients derive differential benefit. Design: This randomized, double-masked clinical trial enrolled 703 immunoco mpetent patients with prior HSV eye disease within the preceding year, assi gned 357 patients to receive oral acyclovir, 800 mg/d, and 346 to receive p lacebo; and followed up patients during a 12-month treatment period for the development of HSV eye disease. Results: The cumulative probability of a recurrence of any type of ocular H SV disease during the 1-year treatment period was 19% in the acyclovir grou p compared with 32% in the placebo group. Sixteen patients in the acyclovir group and 30 in the placebo group had more than 1 recurrence. A benefit wa s seen for preventing both epithelial keratitis (rate ratio, 0.62; 95% conf idence interval, 0.39-0.97) and stromal keratitis (rate ratio, 0.57; 95% co nfidence interval, 0.36-0.89). Although a relative benefit of treatment on preventing any type of recurrence was present in most subgroups, the magnit ude of absolute benefit tvas greatest among patients with the highest numbe r of prior episodes of ocular HSV disease. The benefit in preventing stroma l keratitis was seen solely among patients with a history of stromal kerati tis. Conclusions: Long-term suppressive oral acyclovir therapy reduces the rate of recurrent HSV epithelial keratitis and stromal keratitis. Acyclovir's be nefit is greatest for patients who have experienced prior HSV stromal kerat itis.