The isolation of the herpes simplex virus (HSV) from human trigeminal ganglia explains why attacks of ocular herpetic infection are intermittent and recurrent.1 Because all antiviral medications are virustatic rather than virucidal, treatment with topical and systemic antiviral agents does not affect the dormant virus within the ganglion. It has been known for many years that recurrences of genital infections due to HSV can be suppressed by treatment with prophylactic, daily, low-dose, oral acyclovir.2- 4 Acyclovir, 400 mg given orally twice daily, taken prophylactically for periods ranging from 10 to 34 months, reduces recurrent HSV keratitis.5- 7 I do not believe that the 3-week course of oral acyclovir used in The Herpetic Eye Disease Study Group's8 recently reported study was long enough to protect against recurrences of stromal keratitis or iritis. It is unfortunate that the study design did not include a third treatment group in whom the treatment with oral acyclovir was continued for the entire 1-year follow-up period.
Bachman DM. Prevention of Herpes Simplex Keratitis and Iritis. Arch Ophthalmol. 1998;116(2):259. doi: