OPN may occur as a manifestation of BD and, in non-Western countries, this may be more common than the idiopathic variety. In contrast to idiopathic cases, OPN in BD is more likely to demonstrate initial rapid progression of visual loss and more severe loss at presentation. Patients show less recovery of vision in response to corticosteroids but carry a lower rate of subsequent relapse. Patients with OPN should be specifically questioned regarding symptoms of BD.

NMO antibody positivity is relatively high in Chinese patients with severe ON and suggests a poorer visual outcome, probably higher risk of developing spinal cord lesions and a closer association with systemic autoimmune disorders.