Optic neuritis: experience from a south Indian demyelinating disease registry

Natural history of optic neuritis (OPN) has not been studied in India.

To study consecutive patients with optic neuritis as the initial manifestation of the neurologic disease and with disease duration of 3 or more years registered in the Mangalore Demyelinating Disease Registry.

The study included 59 patients with a primary diagnosis of optic neuritis (confirmed by either an ophthalmologist or a neurologist or both). All the patients were investigated and followed-up in the clinic.

During the follow-up of the 59 patients, 29 (49%) patients developed multiple sclerosis (MS); 3 (5%) patients neuromyelitis optica (NMO); and 13 (22%) patients chronic relapsing inflammatory optic neuritis (CRION), while the remaining 14 (24%) did not either progress or relapse, monophasic OPN. An initial abnormal magnetic resonance imaging predicted conversion to MS in all 7 patients who had imaging at onset. Patients with NMO were left with significant residual visual loss distinguishing NMO from MS. In this large series of patients with CRION, nearly 50% of patients had deterioration in vision while steroids were being tapered. Long-term immunosuppression was essential for maintaining good visual outcome in both NMO and CRION.

Optic neuritis in India appears similar to that in the West with nearly 50% developing MS in the long term.