Late varicella-zoster virus dendriform keratitis in patients with histories of herpes zoster ophthalmicus.

PURPOSE: To describe the characteristics and course of late varicella-zoster virus (VZV) dendriform keratitis in patients with histories of herpes zoster ophthalmicus (HZO); to describe responses of corneal lesions to antiviral treatment; and to investigate risk factors for recurrence. DESIGN: Retrospective case series. METHODS: Included were patients known to have 1 or more episodes of dendriform lesions beginning at least 2 weeks after HZO in 2 academic practices. Epithelial lesions were evaluated for the presence of VZV DNA by a polymerase chain reaction assay. Demographic, medical, and ophthalmic data were collected for each episode. Responses to treatment with antiviral medications were evaluated. Cumulative risk of recurrence was determined using Kaplan-Meier analysis; potential risk factors for recurrence (age, systemic disease, lesion characteristics, corticosteroids) were evaluated using univariate Cox proportional hazard models. RESULTS: We identified 20 patients (14 women; median age, 65 years) who met inclusion criteria. Dendriform lesions were pleomorphic with thickened, opaque epithelium. Seven patients had systemic diseases characterized by altered immune function. VZV DNA was identified in 15 of 16 cases tested, and all lesions responded to antiviral therapy. The 1-year incidence of first recurrence was 95.8 lesions per 100 person-years of follow-up. Patients had multiple recurrences, but risk of recurrence appeared to decrease over time. No statistically significant risk factors for recurrence were identified. CONCLUSIONS: Late dendriform lesions associated with HZO are foci of productive VZV infection. Lesions can be treated effectively with topical or systemic antiviral agents. Patients can have multiple recurrences of dendriform lesions despite treatment.