A controlled trial of oral acyclovir for iridocyclitis caused by herpes simplex virus. The Herpetic Eye Disease Study Group.

OBJECTIVE: To assess the benefit of adding oral acyclovir to a regimen of topical prednisolone phosphate and trifluridine for the treatment of iridocyclitis caused by herpes simplex virus (HSV).

METHODS: Patients with HSV iridocyclitis were enrolled in a multicenter controlled clinical trial supported by the National Eye Institute, Bethesda, Md, and randomly assigned to receive a 10-week course of either oral acyclovir, 400 mg, 5 times daily, or oral placebo in conjunction with regimens of topical trifluridine and a topical corticosteroid. Follow-up examinations were performed weekly during the 10-week treatment period, every 2 weeks for an additional 6 weeks, and at 26 weeks after enrollment in the trial. Treatment failure was defined as a persistence or worsening of ocular inflammation, withdrawal of medication because of toxicity, or a request by the patient to withdraw from the trial for any reason. The trial was stopped because of slow recruitment after only 50 of the originally planned 104 patients were enrolled in more than 4 years.

RESULTS: A treatment failure occurred in 11 (50%) of the 22 patients in the acyclovir-treated group and in 19 (68%) of the 28 patients in the placebo group. Compared with the placebo group, the adjusted rate ratio for a treatment failure in the acyclovir-treated group during the 10-week treatment period was 0.43 (90% confidence interval, 0.18-1.02; P = .06, 1-tailed) and during the 16-week follow-up period (10-week treatment period plus 6-week observation period) was 0.60 (90% confidence interval, 0.29-1.25; P = .13, 1-tailed in a proportional hazards model). The treatment effect seemed slightly greater when only the patients with a persistence or worsening of ocular HSV disease were considered as treatment failures (ie, excludes terminations because of toxic effects of the drug and patients who requested to withdraw from the trial). By life-table analysis, similar results were obtained; the possible benefit of acyclovir became apparent after the first 3 weeks of follow-up.

CONCLUSION: While the number of patients recruited in this trial was too small to achieve statistically conclusive results, the trend in the results suggests a benefit of oral acyclovir in the treatment of HSV iridocyclitis in patients receiving topical corticosteroids and trifluridine prophylaxis.