Acute retinal necrosis: Report 1—Epidemiology, clinical profile, and misdiagnosis from the largest Indian case series

PURPOSE: To describe the clinical profile of a large cohort of patients with acute retinal necrosis (ARN) in a tertiary eyecare institute from India. METHODS: Retrospective analysis of all patients with ARN, visiting the uveitis clinic of a tertiary eye institute between 2010 and 2022. RESULT: The study included 144 eyes of 119 patients with ARN (mean age 37.6 ± 15.8 years); 68.6% were males. A history of chickenpox was present in 12.6% and viral encephalitis in 9.2%. The common presenting symptom was blurred vision (94.9%), followed by redness (28.8%), pain (24.6%), and floaters (15.3%). Misdiagnosis occurred in 36.9% of cases. At presentation, 79.0% had unilateral disease, while 21.0% were bilateral, with many showing sequential involvement after a mean interval of 5.9 years. Anterior uveitis was documented in 30.5% of eyes, vitritis grade ≥ II in 70.8%, and all four quadrants of retinitis in 47.8%. Retinal vasculitis and optic nerve involvement were noted in 84.0% and 39.6%, respectively. Polymerase chain reaction detected herpes simplex virus and varicella-zoster virus with equal frequency (28.6% each); dual infection was found in 5.0%. Most patients received intravenous acyclovir induction followed by oral antivirals, with valacyclovir used in 80.7%. The mean treatment duration was 5 months. Follow-up averaged 2 years, during which the visual acuity declined from 1.58 to 1.89 logMAR. Major complications included cataract (79.2%), retinal detachment (72.5%), hypotony (48.6%), and optic atrophy (25%). CONCLUSION: ARN remains a devastating viral retinitis which is frequently underrecognized in its early stages.