075 Herpes Simplex retinitis in a patient with prior Herpes Simplex encephalitis

Herpes Simplex virus (HSV) retinitis is a rapid onset condition which, if untreated, can cause extensive irreversible visual loss. It may arise in immunocompetent patients without clear precipitant. We report a patient in whom HSV encephalitis was diagnosed on the basis of clinical picture, imaging findings and positive PCR for HSV1. She was treated with IV Aciclovir and recovered with some residual impairment of cognitive function. One year later, she developed blurred vision for 3 days followed by a painful, red eye. The retina was elevated and the optic disc swollen. PCR on fluid from an anterior chamber tap was positive for HSV1 demonstrating HSV retinitis. Treatment was instituted with intravenous aciclovir however her acuity in that eye declined to counting fingers only. Extensive investigation showed no immune deficit. Review of the literature demonstrates several case reports and small series of patients who have developed HSV retinitis having previously developed HSV encephalitis. This case illustrates the apparently higher risk of HSV retinitis in patients who have previously developed HSV encephalitis. As early recognition and treatment of this condition may affect outcome, we consider this of relevance to practicing neurologists.