Optic Neuritis Study Group
Archives of Ophthalmology. 2003;121(7):944-949
The Optic Neuritis Treatment Trial (ONTT) has provided a wealth of information on patients with a first episode of acute demyelinating optic neuritis. In the trial, patients with optic neuritis were randomized to receive intravenous corticosteroids followed by oral corticosteroids, oral corticosteroids alone, or placebo, and followed over time. The ONTT showed that the risk of developing clinically defined multiple sclerosis (MS) is largely determined by the number and characteristics of other demyelinating lesions within the brain on magnetic resonance imaging (MRI). Until this report, the data from the ONTT had been gathered over a 5-year follow-up after the patients were enrolled into the study.
The purpose of this report was to identify factors associated with a higher and lower risk of developing MS after an initial bout of optic neuritis. The authors of this multicenter study originally followed 388 patients with optic neuritis. These patients were reassessed 10-13 years after their enrollment.
There were 336 patients reassessed at the 10-year time point. The 10-year risk of developing MS was 38% (95% confidence interval 33% to 43%). Those patients who had abnormal brain MRI scans (with the presence of a white matter T2-signal abnormality of at least 3 mm in size) at study enrollment were significantly more likely to develop MS than those with normal MRI scans (56% vs 22%, P < .001). In patients who had normal MRI scans at study enrollment, factors associated with a lower risk of subsequent MS included: male gender, the presence of optic disc swelling in the affected eye, no light perception at study enrollment, the absence of pain with eye movement, severe optic disc edema, peripapillary hemorrhages, and retinal exudates.
This study provides clinically important information for patients with optic neuritis and without a history of prior MS. An abnormal MRI scan at the time of acute demyelinating optic neuritis is predictive of subsequent MS. The presence of one T2-weighted signal abnormality characteristic of demyelination doubles the risk of subsequent MS over a 10-year period. In patients with normal MRI scans at the time of the acute episode, a number of clinical features can suggest a lower risk of subsequent MS. RF
Optic Neuritis Study Group. The 5-year risk of MS after optic neuritis:
experience of the Optic Neuritis Treatment Trial. Neurology. 1997;49:1404-1413.
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