Optic Neuritis is due to inflammation of the covering (myelin) of the neurons within the optic nerve. Vision loss is rapid, severe, and often associated with pain with eye movement. Vision loss stops in about a week. Usually patients regain most of their vision within a month.
About half of patients with Optic Neuritis have evidence of similar lesions elsewhere in their brain. MRI is a useful test to assess for brain lesions. Sometimes, numerous brain lesions may be an indicator for the presence of Multiple Sclerosis (MS).
There is no treatment that alters the long term vision in patients with Optic Neuritis. In those with other brain findings consistent with early MS, steroids and beta interferon may decrease the likelihood of developing progressive disease.