Measles-Related Macular Necrotizing Retinitis in an Unvaccinated Adult: A Case Report.

PURPOSE: To describe the clinical features, multimodal imaging (MMI) findings, and therapeutic management in a case of asynchronous bilateral macular necrotizing measles-related retinitis in an unvaccinated adult. METHODS: Observational case report. RESULTS: A 36-year-old unvaccinated male presented with acute vision loss in the right eye. He had a past history of idiopathic encephalitis and prior necrotizing retinitis in the contralateral eye. MMI revealed full-thickness macular retinitis with the characteristic "moth-eaten" appearance accompanied by the "ballooning" of an intact internal limiting membrane (ILM) on optical coherence tomography (OCT). Both intraocular fluid and cerebrospinal fluid (CSF) PCR, and the CSF/serum measles-specific antibody index, were non-diagnostic contributory, a known limitation in late-onset, compartmentalized measles complications. Diagnosis was reached through integration of clinical history, systemic seropositivity, and hallmark MMI features. A combined treatment regimen of remdesivir, pegylated interferon alpha-2a, and intravenous immunoglobulin (IVIg) appeared to halt disease progression and preserved central vision. CONCLUSION: Late-onset measles retinitis poses a significant diagnostic challenge, as negative direct molecular testing may mislead clinicians and delay appropriate treatment. This case underscores the critical role of systemic serology, MMI, and structured clinical reasoning in reaching a timely diagnosis. In an era of declining vaccination coverage, clinicians should maintain a high index of suspicion for measles-related ocular complications.