VOR REFLEX

SYMPTOMS

Patients with impaired VOR function cannot produce adequate compensatory eye movements. In simpler terms, your eyes will fail to coordinate with the movement of your head. Furthermore, an impaired VOR is likely to cause oscillopsia, which causes blurry or jumpy vision.

DIAGNOSIS

In order to see if your VOR works fine, here are some tests you can take:

• Head Impulse Testing (HIT)

The head impulse or head thrust test detects VOR deficits in the lateral, superior, and posterior semicircular canals. It is capable of detecting unilateral and bilateral peripheral lesions with high accuracy.

• Rotational Chair Testing

This test activates both canals and provides details about the vestibular system’s overall role during head rotation. 

• Sinusoidal harmonic acceleration testing

The chair pushes in a sinusoidal pattern which facilitates the study of eye movements in response to angular accelerations of different magnitudes. 

• Constant angular acceleration

The chair’s rotational velocity is raised at a constant rate of 360° until it reaches its full speed. 

• Impulse angular acceleration

This test is often used to diagnose nystagmus and is conducted by performing an acceleration test in both directions.

• Velocity step test

In this test, a high velocity is conducted first before rapidly decreasing it. Afterward, the data gathered, including the time and gain value, is measured.

• Caloric testing

Caloric irrigation induces changes in endolymph density by generating a temperature gradient around the stimulated ear’s lateral semicircular canal. 

The vestibulo-ocular reflex aids the human body in maintaining balance. Hence, if your vision suddenly becomes blurry, jumpy, or if objects look like they are in motion despite staying still, consult your doctor. These may be signs of an impaired VOR reflex.