Acute-onset bilateral visual loss in the context of longstanding myasthenia gravis: don’t forget anti-aquaporin-4 antibodies!

Abstract

Acute-onset visual loss is a medical emergency necessitating prompt and timely intervention to preserve vision and prevent further deterioration. Besides ocular pathologies, neurological conditions account for a significant proportion of cases of visual loss, particularly optic nerve pathologies including demyelinating or inflammatory optic neuritis. Inflammatory optic neuritis may cause unilateral or bilateral acute visual loss in isolation, as the first presentation of multiple sclerosis or neuromyelitis optica spectrum disorder, or in association with systemic autoimmune conditions. We hereby present a case of sequential bilateral anti-aquaporin-4 autoantibody-positive optic neuritis presenting as acute bilateral visual loss and initially diagnosed as temporal arteritis in a patient with longstanding myasthenia gravis. Our case highlights the importance of timely recognition of the possibility of optic neuritis when assessing acute visual loss, and the need for prompt initiation of corticosteroid therapy for residual vision preservation. It also illustrates the importance of maintaining awareness of possible neuromyelitis optica spectrum disorders and diligently testing for anti-aquaporin-4 antibodies in patients presenting with ocular symptoms in the context of co-existing autoimmune pathology and no other obviously attributable ophthalmological pathologies.