Oculomotor and nystagmus tests in subjects with strabismus

Smooth pursuit (SP) and saccades (SC) as well as nystagmus were recorded with electro-oculography in 21 healthy subjects with manifest non-paralytic strabismus. A normal SP function under binocular conditions could be recorded in 67% of the subjects and complementary monocular recordings increased the figure to 81%. The corresponding figure for the SC test was 38 and 67%, respectively. However, a minority of the subjects presented a normal test result under both binocular and monocular conditions. Spontaneous nystagmus and/or nystagmus after headshaking was present in 67%. These findings may indicate that subjects with strabismus have a combination of a 'subclinical' vestibular and oculomotor dysfunction.