STRABISMUS RESULTING FROM LESIONS IN THE PERIPHERAL VESTIBULAR SYSTEM

Little attention has been paid in the ophthalmological literature to strabismus resulting from lesions located in the peripheral vestibular system. However, this phenomenon is commonly encountered in clinical pratice. As a rule, this kind of strabismus shows a prominent vertical component. It is generally combined with a change in perception of verticality, conjugate cyclotorsion of the eyes, and head tilt. This association is known as "ocular tilt reaction". It occurs in a number of clinical settings which are believed to be related with alteration in the otolithical and/or vertical semicircular canal pathways. Strabismus occurring as a feature of ocular tilt reaction might result from different mechanisms according to the location of the lesion, e.g. in the utricles, in the midbrain tegmentum, and in the dorso-lateral medulla oblongata. This phenomenon is illustrated here with the report of a patient suffering from Meniere disease, who underwent selective vestibular neurectomy. Methods of ophthalmological evaluation in such cases is described.