Multiple branch retinal arteriolar occlusions associated with smallpox vaccination

Summary We describe a rare combination of multiple multiple branch retinal arteriolar occlusions (BRAO) and encephalopathy, which developed in an adult male 10 days after smallpox vaccination. A 53-year-old physician presented with sudden temporal visual field loss in the left eye. Ten days earlier he had received a smallpox vaccination. Hyperbaric oxygen was administered because of suspected BRAO. Examination on day 3 revealed a decrease in visual acuity and loss of visual field. Fundoscopy of the left eye disclosed a retinal infarct in the inferior macula and multiple cotton wool spots over the entire posterior pole. Fluorescein angiography showed delayed arterial filling and multiple non-perfused areas. Magnetic resonance imaging of the brain disclosed white matter focal lesions. Neurological examination was normal. Audiological examination revealed mild hearing loss caused by an old phonic trauma. A combination of intravenous methylprednisolone and immunoglobulins, recommended for the treatment of Susac syndrome, was administered. At the follow-up visit 3 months later, visual acuity in the left eye improved, fundoscopy showed resolution of the cotton wool spots and temporal disc pallor, and the visual field was substantially restored.