In the past, controversy existed as to whether or not to treat patients with ON with corticosteroids. The Optic Neuritis Treatment Trial (ONTT) supports the administration of intravenous methylprednisolone sodium succinate (Solumedrol, 250 mg. every 6 hours) for three days followed by oral prednisone (1 mg/kg per day) for 11 days for the purposes of accelerating visual recovery. This therapy did not improve visual outcome after one year but was found to increase the rate at which patients recover. The ONTT also determined that the use of oral prednisone (1 mg/kg per day) alone for 14 days is contraindicated. Patients receiving this therapy had a higher rate of new attacks of ON in both the initially affected and fellow eyes than did the intravenous/oral group and placebo group. As recorded in the three-year follow-up of patients in the ONTT, treatment with intravenous methylprednisolone followed by oral corticosteroid regimens reduced the two-year rate of development of clinical MS, particularly in patients with signal abnormalities consistent with demyelination on MRI of the brain at the time of study entry. Serious side effects of glucocorticoid therapy are infrequent. Therefore, outpatient administration of high-dose intravenous glucocorticoids may be recommended.