Real-time polymerase chain reaction in acute retinal necrosis following encephalitis

Acute retinal necrosis (ARN) following herpes simplex encephalitis (HSE) in an immunocompetent patient is a rare condition. Quantitative real-time polymerase chain reaction (qPCR) has made it possible to identify and quantify viral genome. We report a case of ARN following HSE managed with the help of qPCR. A 45-year-old man developed ARN following HSE and was treated with intravenous acyclovir and intravitreal foscarnet. The retinitis did not respond initially and the qPCR demonstrated a rise in the number of copies of the HSV-1 viral genome. With continued treatment with intravenous acyclovir and intravitreal ganciclovir, the retinitis healed and the qPCR confirmed a reduction in the viral load. qPCR has a high sensitivity and specificity for HSV and is a useful tool for diagnosis and treatment of viral retinitis.