Purpose: Review of the association between optic neuritis (ON) and multiple sclerosis (MS).

Results: MS often presents as acute unilateral ON. While it is clear that many patients with ON suffer from a generalized disease of the central nervous system that will go on to clinically definite MS (CDMS), it is also clear that others do not. With more and more well‐informed patients and the emerging pharmacotheraphy for MS, the distinction between those patients with ON who have MS and those who do not, has become more important than ever before. Recently, a large randomized clinical trial on patients with ON or other clinically isolated syndromes suggestive of MS and evidence of prior subclinical demyelination on magnetic resonance imaging of the brain, found that treatment with recombinant interferon‐beta‐1a is beneficial by reducing the development of CDMS.

Conclusion: Ophthalmologists should refer their patients with acute ON to a neurologist for MS‐directed investigations and decisions regarding early institution of disease modifying therapy.