Purpose: To describe 4 cases of presumably immunocompetent patients with herpes simplex virus (HSV) keratitis unresponsive (n = 3) or allergic (n = 1) to conventional antiviral therapy that improved with oral valganciclovir treatment.

Methods: Retrospective case series of 4 patients with HSV keratitis treated with oral valganciclovir between March 2016 and June 2018.

Results: We reviewed the records of 4 patients with recurrent epithelial HSV keratitis. Three patients were on antiviral prophylaxis because of a history of HSV keratitis. All patients were on oral acyclovir, valacyclovir, and/or famciclovir treatment with/without topical antiviral therapy for 4 to 6 months for prophylaxis and/or recurrent dendriform epithelial keratitis. While 3 patients had recurrent episodes during their active prophylaxis with oral antiviral therapies, one patient had a recurrence after she discontinued her oral prophylactic antiviral therapy due to recurrent self-reported allergic reactions. The patients presented with recurrent dendriform epithelial keratitis despite conventional antiviral therapy. We initiated oral valganciclovir 900 mg twice a day for 10 days as a treatment dose, followed by 900 mg daily for prophylaxis. The corneal epithelium subsequently healed within the first 2 weeks in all patients. The mean follow-up time for patients on valganciclovir prophylaxis was 8 months (range: 6-12 months), and none of the patients presented with any further recurrences.

Conclusions: In case of treatment-related side effects or failure with conventional antiviral therapies, oral valganciclovir may present an alternative for the treatment and prophylaxis of HSV keratitis.