Optic Neuritis Treatment Trial (ONTT)

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    Start with IV and you’ll be full of glee; go straight to PO and you’ll be saying “No!”  The Optic Neuritis Treatment Trial (ONTT) sought to determine the optimal treatment for acute optic neuritis. Patients with acute optic neuritis (aged 18-46), excluding those with previous optic neuritis in the same eye, were randomized to three groups: placebo (n = 150), IV methylprednisolone x3 days followed by oral prednisone x11 days (n = 151), and oral prednisone x14 days (n = 156).

Key Points:

• The IV methylprednisolone group had quicker recovery compared to the placebo (and oral prednisone group), though there was no large difference in visual acuity at 6 months
• The oral prednisone group had an increased risk of repeat optic neuritis (RR 1.79 vs. placebo)
• At 15 years, the cumulative probability of developing MS after an episode of optic neuritis was 50%; 25% if no MRI lesions at baseline, 72% if there were.  

Overall, the ONTT is a landmark study because led to a major shift in the treatment of optic neuritis. Before the trial, there was no clear treatment protocol, and the use of corticosteroids was questioned. The study clearly showed that treatment should start with IV methylprednisolone and should avoid starting with oral prednisone. It also showed that the presence of MRI lesions was a key prognostic indicator for the development of MS.