Pursuit is impaired but the vestibulo-ocular reflex is normal in infantile strabismus

To determine if infantile (congenital) strabismus is associated with a defect of ocular pursuit or vestibulo-ocular reflexes, eye movements were recorded in 14 subjects. Subjects with infantile strabismus had an impairment of temporally directed pursuit when monocularly viewing a moving target. They were unable to normally enhance or cancel the vestibulo-ocular reflex using visual tracking. Vestibulo-ocular reflexes were normal during rotation at 0.3 Hz in the dark. The pursuit defect was not found in subjects with noninfantile strabismus. We suggest that patients with infantile strabismus have a defect of cerebral pursuit control.