The Optic Neuritis Treatment Trial

T HE OPTIC NEURITIS TREATMENT TRIAL (ONTT)hashadahighly significant impact on thepracticesofophthalmologyandneurology. The impact can be attributed to its systematic collection and analysis of enormousamountsofdata,adherencetosoundclinicaltrialmethodology, as well as important unanticipated findings. For lack of a more precise definition, optic neuritis is an acute, noninfectious inflammatory optic neuropathy that predominantly affects young people. By the end of the 19th century, the clinical profile of this disorder and its relationship to multiple sclerosis (MS) were well characterized. In the subsequent 100 years, numerous reports identifying erroneous etiologies and seemingly successful