The natural history of optic neuritis in Asian patients: An observational cohort study

Optic neuritis, which may be a precursor to multiple sclerosis (MS), is an uncommon disease in Asian patients. The Asian Collaborative Longitudinal Optic Neuritis Epidemiology (ACLONE) is an observational cohort study that assessed the risk of recurrent optic neuritis and/or progression of further neurologic events, either MS or neuromyelitis optica (NMO) in Asian patients with first-ever optic neuritis. Secondary aims were to study the presenting characteristics and visual outcome, and to identify risk factors for development of either MS or NMO. A total of 112 patients (25 men and 87 women) aged from 12 to 61 years were recruited from Singapore, Taiwan, South Korea and Malaysia. Of these, 94 (84%) had unilateral optic neuritis, with the right eye involved in 45 patients and the left eye in 49 patients and the remaining 18 (16%) had bilateral optic neuritis. Follow up data was available for 104 patients, and patients were followed for a median duration of 25.9 months. Of these patients, 6 patients were adjudicated to have reached the primary endpoint (composite of MS/NMO and optic neuritis): 3 patients with recurrent optic neuritis also subsequently experienced neurologic symptoms, and 3 patients without recurrent eye involvement had neurologic symptoms. Only one patient was considered to have prototypical MS, the other 5 were diagnosed with NMO, all with subsequent antibody confirmation. Optic neuritis in Asian patients has significantly different presenting characteristics from the classic description. However, in the majority of the patients it is usually a benign disease, with good visual outcome and no further events.