Evaluation of transdermal scopolamine as treatment for acquired nystagmus.

We conducted an unmasked evaluation of transdermal scopolamine in seven patients with acquired nystagmus for whom other treatments had been unsatisfactory. We measured eye speed and visual acuity before and several hours after starting treatment. Median eye speed decreased slightly in three patients but increased in two; no change in visual acuity occurred in any patient. One patient was unable to tolerate the side effects of scopolamine after two hours, but the others continued the scopolamine treatment for 48 hours; only one reported minor improvement. We conclude that transdermal scopolamine is not likely to be an effective treatment of acquired nystagmus. Patients should be monitored during the first few hours of treatment to determine whether vision is improved or made worse and whether side effects occur.