Optic Neuritis

Patients with signs and symptoms consistent with acute monosymptomatic optic neuritis should undergo evaluation with gadolinium-enhanced MRI of the brain and orbits to determine whether or not they are at high risk for the development of clinically definite multiple sclerosis (CDMS). The presence of two or more white matter lesions (3 mm or larger in diameter, at least one lesion periventricular or ovoid) suggests high risk for CDMS, and should prompt immediate treatment as follows: Intravenous methylprednisolone sodium succinate (1 g intravenously per day for 3 days) followed by oral prednisone (1 mg/kg per day for 11 days) with a 4-day taper (20 mg on day 1, 10 mg on days 2 and 4). Interferon beta 1-a, which has been demonstrated to significantly reduce the 3-year probability of the development of CDMS and the development of clinically silent MRI lesions in high-risk patients with acute optic neuritis, should be considered following IV methylprednisolone treatment (30 &mgr;g intramuscularly weekly). In monosymptomatic patients with fewer than two white matter lesions by MRI, and in patients for whom a diagnosis of CDMS has been established, treatment with IV methylprednisolone followed by oral prednisone (as outlined), should be considered on an individual basis and may hasten visual recovery, but has not been demonstrated to affect long-term visual outcome. In all cases of typical acute monosymptomatic demyelinating optic neuritis, oral prednisone alone at a dose of 1 mg/kg per day, without prior treatment with IV methylprednisolone (1 g per day for 3 days), may increase the risk for recurrent optic neuritis, and should be avoided.