EFFECTS OF INTRAVENOUS METHYLPREDNISOLONE ON OUTCOME IN MRI-BASED PROGNOSTIC SUBGROUPS IN ACUTE OPTIC NEURITIS

Treatment of acute optic neuritis with steroids has been shown to hast en visual recovery without affecting the final degree of recovery. How ever, MRI-clinical studies indicate that patients with long optic nerv e lesions, particularly those that involve the nerve within the optic canal, may have a worse prognosis for recovery of vision. Partly becau se such lesions could lead to swelling and subsequent ischemic optic n erve damage, steroids could have a selective beneficial effect on this subgroup of patients. The present randomized trial was designed to te st this possibility. Sixty-six patients with acute optic neuritis rece ived IV saline or IV methylprednisolone. The clinical, psychophysical, electrophysiologic, and MRI outcomes were assessed after 6 months. Pa tients with short lesions presented earlier than those with long lesio ns (involving three or more 5-mm-thick slices of any part of the optic nerve, as well as its intracanalicular portion), and lesion length wa s significantly less in patients presenting within a week of onset of symptoms. Lesions also tended to lengthen during follow-up in individu al patients. Treatment did not limit lesion length in either the long or short lesion subgroup and had no significant effect on final visual outcome. We conclude that steroids do not improve visual outcome or l esion length in patients with acute optic neuritis.