The effect of oral prednisolone on visual evoked potential latencies in acute optic neuritis monitored in a prospective, randomized, controlled study.

The Tübingen study of optic neuritis treatment was started in 1980 to apply new and sensitive tests for monitoring a potential therapeutical steroid effect on the course of acute optic neuritis. Visual evoked potentials were used to assess an effect of oral methylprednisolone in a randomized, controlled trial. Forty-eight patients with acute optic neuritis were treated orally either with methylprednisolone (100 mg per day initially, dosage reduction every 3 days; n = 15) or with thiamine (100 mg per day; n = 33) in the control group, 36 of them in a double-blind procedure. A comparison of the two treatment groups indicated that oral methylprednisolone resulted in a faster improvement in visual evoked potential latency in the initial phase (p = 0.015, 4 weeks after onset), but had no benefit after 12 weeks and 12 months. Follow-up showed different types of courses in the visual evoked potential latencies. The visual evoked potential latencies were correlated to other outcome variables, such as visual evoked potential amplitudes, visual acuity, Aulhorn flicker test and perimetry. We were able to handle nonmeasurable latencies in highly pathologic cases by means of ranks (taking into account censored observations).