Incidence, recurrence, and outcomes of herpes simplex virus eye disease in Olmsted County, Minnesota, 1976-2007: The effect of oral antiviral prophylaxis

Objectives: To provide an estimate of the incidence of herpes simplex virus (HSV) eye disease in a community-based cohort, and to investigate the effect of prophylactic oral antiviral therapy on HSV recurrences and outcomes. Methods: All Olmsted County, Minnesota, residents diagnosed with ocular HSV from 1976 through 2007 were retrospectively reviewed. The frequency of recurrences and adverse outcomes, such as vision loss or need for surgery, were compared between untreated patients and those treated prophylactically with oral antiviral medication. Results: Three hundred ninety-four patients with ocular HSV were identified, yielding an annual incidence of 11.8 per 100 000 people (95% confidence interval [CI], 10.6-13.0). No trends in incidence or adverse outcomes were identified during the 32-year period. Oral antiviral therapy was prescribed in 175 patients. Patients were 9.4 times more likely (95% CI, 5.0-17.9) to have a recurrence of epithelial keratitis, 8.4 times more likely (95% CI, 5.2-13.7) to have a recurrence of stromal keratitis, and 34.5 times more likely (95% CI, 10.8-111.1) to have a recurrence of blepharitis or conjunctivitis if not being treated prophylactically at the time of the recurrence. Twenty patients experienced adverse outcomes, and 17 (85%) were not being treated with oral antiviral medications immediately preceding the adverse event. Conclusions: Oral antiviral prophylaxis was associated with a decreased risk of recurrence of epithelial keratitis, stromal keratitis, conjunctivitis, and blepharitis due to HSV. Patients with adverse outcomes due to ocular HSV were usually not being treated with oral antiviral prophylaxis.