Severe optic neuritis in a patient with combined neuromyelitis optica spectrum disease and primary Sjögren’s syndrome: a case report

UNLABELLED INTRODUCTION Optic neuritis, although uncommon, can be the initial presentation of Sjögren's syndrome. Coexisting Sjögren's syndrome has also been reported with neuromyelitis optica spectrum disorder. This case report highlights the association between the two diseases and the importance of rheumatological and neurological evaluations in patients with such diagnoses. Distinction of neuromyelitis optica with coexisting connective tissue disease has both prognostic and therapeutic significance for the patient. CASE PRESENTATION We report a case of a 56-year-old Chinese woman who presented with bilateral asymmetric visual loss secondary to optic neuritis. She was subsequently found to be seropositive for neuromyelitis optica immunoglobulin G (NMO-IgG) (anti-aquaporin-4 antibody) and was diagnosed with neuromyelitis optica spectrum disorder. She also fulfilled the international criteria for Sjögren's syndrome. Despite initial high dose immunosuppressive therapy, she failed to regain vision in one eye. CONCLUSION Patients presenting with optic neuritis and severe visual loss should be screened for neuromyelitis optica and treated appropriately. Neuromyelitis optica has been associated with systemic autoimmune diseases, in particular Sjögren's syndrome, and current evidence indicates that they are two distinct entities. We recommend that both diagnoses be considered in cases of optic neuritis with severe visual loss.