“…A recent survey found that by one and six months after the attack, 50%4 and 75%0 respectively ofpatients had regained normal vision (Bradley and Whitty, 1967). Corticotrophin (ACTH) is widely used in the treatment of acute optic neuritis, though the evidence that it favourably affects the natural history comes from one trial in which (1) only patients presenting within 10 days of the onset of visual blurring were included; (2) the only measure of visual function used was acuity for near vision; and (3) significant benefit was shown only in the first month of treatment with corticotrophin gel (Rawson et al, 1966(Rawson et al, , 1969. However, many patients with acute optic neuritis are not seen within 10 days of the onset of visual impairment, and, though their vision may be improving when they are first seen, it is important to know whether to use ACTH.…”