Acute optic neuritis: prognosis for the development of multiple sclerosis.

The literature was reviewed in regard to acute optic neuritis: prognosis for the development of multiple sclerosis, with specific reference to our flying population. Two major factors were found that influence the large discrepancy in statistics. The first was that the patient population, in many series, was preselected and not prospective, causing a higher incidence of later multiple sclerosis. The second factor was the definition of multiple sclerosis used by various groups. When strict criteria were followed for such definition, many of the apparently dissimilar series were, in fact, quite similar. Two series which most closely parallel our flying population are reviewed in detail. Both series suggest a very low incidence of later development of multiple sclerosis in patients affected with acute optic neuritis. This finding leads us to conclude that an incidence of 13% to 17% (calculated on life tables) most accurately represents the risk that our flyers who are afflicted with optic neuritis will later develop multiple sclerosis. (Author)