Walsh & Hoyt: Effects of Drugs on Eye Movements

Many substances affect eye movements. In some cases, the drug induces abnormalities of eye movements at therapeutic concentrations (e.g., anticonvulsants). In other cases, abnormalities of eye movements develop only when concentrations of the drug in the central nervous system are inappropriately elevated. In still other cases, the eye-movement abnormalities are caused by substances not meant for internal use. Patients with drug-induced abnormalities of eye movements most often complain of diplopia, caused by ocular misalignment, or oscillopsia, caused by spontaneous nystagmus or an inappropriate VOR. Many drugs have their effect on central vestibular and cerebellar connections and cause ataxia and gaze-evoked nystagmus.