Herpes Simplex keratitis: epidemiologic aspects.

Review of medical records of 141 patients with acute epithelial herpes simplex keratitis (HSK) showed that recurrences, but not initial episodes, were more likely to happen from November through February than during other months of the year (P less than .04). Other findings included a high male to female ratio in patients older than 40 years of age (1.67:1.0; P less than .03) and a median time interval between episodes (in patients with recurrent disease) of 1.5 years. Although we identified no risk factors for frequent recurrences or for severe disease, our data support the hypothesis that nonherpetic viral respiratory infections may trigger recurrences of HSK.