THERE is a widely held impression that visual deficit due to retrobulbar or optic neuritis is commonly the first sign of multiple sclerosis.1-4 Indeed, an authority5 states that "there is only one common cause of unilateral retrobulbar neuritis, namely, multiple sclerosis." However, the question of whether cases of unexplained and isolated optic neuropathy should be diagnosed as multiple sclerosis is still disputed in the literature. A number of investigators6-11 who followed patients for 10 to 15 years found that about a third of those with unexplained optic neuropathy later developed signs of disseminated neurological deficit. Others12,13 consider that optic neuropathy is rarely followed by neurological deficit compatible with multiple sclerosis.
Besides the question of how frequently patients with optic neuropathy develop disseminated neurological deficit, there is a question of whether those who suffer optic nerve damage at onset of multiple sclerosis differ in clinical course
URI LEIBOWITZ, MILTON ALTER, LIPMAN HALPERN. Clinical Studies of Multiple Sclerosis in IsraelIV. Optic Neuropathy and Multiple Sclerosis. Arch Neurol. 1966;14(5):459–466. doi:10.1001/archneur.1966.00470110003001