Optokinetic test comprising both acceleration and constant velocity stimulation (ACV-OKN test)

Area of Science:

• Neuroscience
• Ophthalmology
• Vestibular System

Background:

• Optokinetic stimulation is crucial for understanding visual-vestibular interactions.
• Previous assessments of optokinetic responses lacked quantitative precision.

Purpose of the Study:

• To introduce a new clinical test for quantitative assessment of optokinetic responses.
• To define and investigate the
• optokinetic fatigue threshold

Main Methods:

• Subjects underwent optokinetic stimulation at varying speeds (60 and 90 degrees/s) with controlled acceleration.
• Eye speed during the slow-phase nystagmus was measured and compared to stimulus velocity.
• Optokinograms were developed for result presentation.

Main Results:

• Eye speed initially matched stimulus speed up to approximately 60 degrees/s.
• Beyond this point, the eye lagged behind the optokinetic stimulus, defining the fatigue threshold.
• Maximum eye speed in the slow-phase nystagmus emerged as the key parameter.

Conclusions:

• The new optokinetic test provides a quantitative measure of visual-vestibular function.
• Abnormal optokinetic responses, identified via optokinograms, are associated with central nervous system and inner ear disorders.
• Maximum slow-phase eye speed is a reliable indicator for clinical assessment.