Normative Values for Instrumented Gaze Stabilization Test and Dynamic Visual Acuity Test Following Fatigue

Individuals with vestibular dysfunction, often report visual blurriness and dizziness. This is often due to gaze instability with walking or with head turns. The cause of this dizziness is due to disruption of the vestibular ocular reflex (VOR). The VOR functions to keep the eyes stabilized on a target while the head is moving. Currently, the best way to measure the integrity of the VOR is with the gaze stabilization test (GST) and the Dynamic Visual Acuity Test (DVAT). The GST is a computerized test that measures the maximum head velocity one can turn their head while maintaining visual fixation on a target. Head velocity is measured in degrees per second. The GST provides information regarding the functional capacity of the vestibulo-ocular reflex. The GST is performed by a clinician with the patient at rest. The dynamic visual acuity test (DVAT) is an established clinical measure of vestibular function. However, research states that high-intensity exercise evokes neurological symptoms in healthy individuals. Clinically, therapists see a drop in gaze stabilization with fatigue. Currently, there are no normative data for gaze stabilization following fatigue. Normative values for how fatigue affects GST and DVA will provide objective information for the function of the vestibular-ocular system, allowing for more accurate management and interventions of individuals with vestibular dysfunction and concussion.