Sudden Vision Loss Due to Optic Neuritis-An Uncommon Presentation of Neurosarcoidosis.

Sarcoidosis is a systemic, granulomatous disease of unknown etiology, most often manifested by mediastinal and hilar lymph node enlargement and parenchymal nodules in the lungs. However, it may involve any other organ. Neuro-sarcoidosis, a condition that affects up to 20% of sarcoidosis patients, can be found in any part of the central or peripheral nervous system and has important ophthalmic and neuro-ophthalmic manifestations. We present two patients with sudden vision loss due to neurosarcoidosis. In both cases, biopsy of the mediastinal lymph node showed non-caseating granulomas consistent with sarcoidosis. Treatment involved high doses of methylprednisolone intravenously, followed by topical dexamethasone eye drops in the first case and a systemic steroid treatment in the second, resulting in symptom relief. Those two cases demonstrate that sarcoidosis should be considered as a differential diagnosis in cases of optic neuritis.