RECURRENT BRANCH RETINAL ARTERY OCCLUSION FROM SUSAC SYNDROME: CASE REPORT AND REVIEW OF LITERATURE Michael J. Ammar, MD,* Anton M. Kolomeyer, MD, PhD,* Nirali Bhatt, MD,* Madhura A. Tamhankar, MD,* Michael T. Mullen, MD,† Alexander J. Brucker, MD* Purpose: We report a patient with branch retinal artery occlusion predominant Susac syndrome and review the literature on current diagnostic modalities and therapeutic approaches for this rare condition. Methods: Case report. Results: A 23-year-old white male presented with a 5-month history of a scotoma in his right eye vision, headaches, and intermittent paresthesias of the lower extremities. Ophthalmic examination was normal with the exception of a hypopigmented small retinal area inferonasal to the fovea in the right eye. Optical coherence tomography demonstrated inner retinal atrophy and optical coherence tomography angiography showed deep capillary layer vessel dropout in both eyes. Ultra-wide-field fluorescein angiography revealed bilateral arteriolar wall hyperfluorescence. Corpus callosal lesions were present on magnetic resonance imaging. Lumbar puncture demonstrated elevated protein. Audio- gram was normal. A diagnosis of Susac syndrome was made. The patient initially received oral steroids followed by intravenous steroids and mycophenolate mofetil because of new branch retinal artery occlusions. Thirteen months after initial presentation, the vision was stable at 20/20 in both eyes. Conclusion: It is a diagnostic challenge when recurrent branch retinal artery occlusion secondary to Susac syndrome presents without the classic symptoms. Optical coherence tomography angiography and subtle magnetic resonance imaging findings aided in early recognition of the diagnosis in our patient. Ultra-wide-field fluorescein angiography was an important tool in disease monitoring. Aggressive management with intravenous cortico- steroids and initiation of immunosuppression resulted in long-term preservation of vision and improvement in visual field. RETINAL CASES & BRIEF REPORTS 0:1–6, 2018 From the *Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; and †Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. O riginally described in 1979, Susac (or Susac– Selhorst) syndrome is a rare autoimmune micro- angiopathy that affects precapillary arterioles of the brain, retina, and inner ear. Although young women in the second to fourth decades of life are most com- monly affected, the syndrome has been diagnosed in those 7 years to 72 years of age. 1–4 Recent reports suggest that the classic triad of branch retinal artery occlusion (BRAO), encephalopathy, and hearing loss occurs in only 13% of patients at presentation, and initially affected individuals may only have ophthal- mologic manifestations. 5 A high index of suspicion is required in such patients to prevent permanent vision loss. 5 The pathophysiology is believed to involve an immune-modulated endotheliopathy that leads to inflammation followed by vessel occlusion and ischemia. 6 Antiendothelial cell antibodies have been 1 Copyright ª by Ophthalmic Communications Society, Inc. Unauthorized reproduction of this article is prohibited.