Walsh & Hoyt: Acute Idiopathic Demyelinating Optic Neuritis

Acute demyelinating optic neuritis is by far the most common type of optic neuritis throughout the world. It is also the type that is best known and understood. Although the clinical syndrome of acute optic neuritis has been well recognizedfor many years, much information about optic neuritis was obtainedfrom the ONTT, a multicenter controlledclinical trial fundedby the National Eye Institute of the National Institutes of Health in the UnitedStates. This trial was the first in the fieldof MS research to look rigorously at a treatment outcome as well as to define metrics of outcome. The ONTT enrolled455 patients with acute unilateral optic neuritis. Although the primary objective of the trial was to assess the efficacy of corticosteroids in the treatment of optic neuritis, the trial also provided invaluable information about the clinical profile of optic neuritis, its natural history, andits relationship to MS.