A case report of isolated primary herpes-simplex virus neuroretinitis in an immunocompetent adult

BACKGROUND: Herpes simplex virus (specifically HSV-1 and HSV-2) are greatly prevalent viruses that can cause conjunctivitis, keratitis and other rarer ocular disorders such as acute retinal necrosis syndrome or neuroretinitis. We report a case of an isolated unilateral neuroretinitis with primary HSV infection in an immunocompetent adult without other related clinical features. CASE PRESENTATION: A 60-year-old immunocompetent woman presented with sudden painless central vision loss in her left eye (best corrected visual acuity was 20/200) showing optic disc edema, submacular fluid and a delayed development of a macular star. The macular optical coherence tomography (OCT) showed a serous retinal detachment. Arterial hypertension or exposure to ionizing radiation were ruled out and the microbiological blood test battery was only positive for immunoglobulin M (IgM) for HSV-1 which allowed etiological treatment with oral valacyclovir. Complete resolution and good visual results were found within 3 months. CONCLUSIONS: The present case of isolated neuroretinitis as a primary HSV infection in an immunocompetent patient was resolved with good functional results after valacyclovir treatment. Presence of HSV IgM in absence of other laboratory results could be enough evidence to start HSV treatment in immunocompetent patients with a macular star, as an isolated lesion, after ruling out other non-infectious causes, such as arterial hypertension or exposure to ionizing radiation. Rare infectious agents in immunocompetent patients must be considered in the differential diagnosis of neuroretinitis, even if there are no other typical symptoms or signs that could suggest the disease.