Exacerbation of Susac Syndrome Retinopathy by Interferon Beta-1a

Susac syndrome features the triad of multiple branch retinal artery occlusions, hearing loss due to microinfarctions of the cochlea, and encephalopathy due to brain microangiopathy.1 Initial misdiagnosis as multiple sclerosis (MS) is not uncommon.1,2 Magnetic resonance imaging evidence of microinfarctions of the corpus callosum and multiple yellow retinal arterial wall plaques on fundus examination are helpful in differentiating this condition from demyelinating diseases.2,3