severe simultaneous bilateral optic neuritis as a rare clinical manifestation in a case of multiple sclerosis presented with acute bilateral vision loss in the emergency department

Background: ophthalmological emergencies typically present with symptoms such as visual loss, diplopia, ocular motility impairment, or anisocoria. acute vision loss is a frightening manifestation for both patients and physicians which can occur as one or both eyes involvement. it is a common manifestation in patients with multiple sclerosis (ms) and the most common cause is optic neuritis (on). on is almost always unilateral in subjects with ms and simultaneous bilateral on has been rarely reported. case presentation: here, we report a case of a female patient with a history of ms, who presented with simultaneous bilateral and progressive vision loss. on in this patient did not respond dramatically to high doses of intravenous methylprednisolone. so, she received intravenous humanized monoclonal anti-cd20 antibody therapy (ocrelizumab). conclusion: this report aims to introduce a very rare case, with regard to the key points for evaluating patients with acute visual loss in the emergency department.