Long-term visual function favorable after optic neuritis

The final report of the Optic Neuritis Treatment Trial (ONTT) showed that the long-term visual outcome is favorable for patients with unilateral acute optic neuritis even in the presence of multiple sclerosis (MS). The investigators determined that magnetic resonance imaging (MRI) is a valuable prognostic indicator. David Kauffman, DO, from East Lansing, MI, reported the findings on behalf of the Optic Neuritis Study Group at the annual meeting of the American Academy of Ophthalmology.

The major findings of the ONTT are that most patients recover vision and remain stable over 15 years, higher doses of intravenous steroids help recovery but do not affect the degree of recovery, about 50% of patients develop MS at 15 years after optic neuritis, and MRI assists in determining which patients will develop MS, Dr. Kaufmann emphasized.

Most patients (92%) had 20/40 or better vision. Patients with no baseline abnormalities on MRI developed MS in 25% of cases; those with one or more abnormalities on MRI developed MS in 72% of cases. When there were no abnormalities on MRI at 10 years, the investigators found a 2% risk of developing MS. When there were one or more lesions at 10 years, there was a 32% chance of developing MS between the 10- and 15-year time points, according to Dr. Kaufmann.

"Neurologic function is important to consider. Fifty percent of patients develop definite MS over 15 years; this is important because by understanding the important clinical features, prognosis is possible as the start of the disease process," Dr. Kaufmann said.

The factors that increase the risk of developing MS include female gender, a viral syndrome, and a normal optic disc along with a normal MRI. "In women, the chance of developing MS is more than half again that of those with a normal disc and a normal MRI. Considering the same scenario in men, only a small fraction developed MS," he emphasized.