Focused Update on Clinical Testing of Otolith Organs

Abstract

The overall contribution of otolith receptors to eye movements, postural control and perceptual functions is the basis for clinical testing of otolith function. With such wide range of contributions, it is important to recognize that the functional outcomes of these tests may vary depending on the specific method employed to stimulate the hair cells. In this article, we review common methods used for clinical evaluation of otolith function and how different aspects of physiology may affect the functional measurements in these tests. We compare the properties and performance of various clinical tests with the emphasis on the newly-developed video ocular counter roll (vOCR), measurement of ocular torsion on fundus photography, and subjective visual vertical or horizontal (SVV/SVH) testing.