Eye Movement Protocol Utilizing Sinusoidal Smooth Pursuit Stimulus: Investigating Gain and RMSE in Healthy Individuals

Abstract

Background: Metabolic disorders have been associated with a wide range of physiological disturbances, and emerging research has suggested a potential link between metabolic health and eye movement parameters. As eye movement abnormalities may provide valuable insights into the underlying neurophysiological mechanisms, the present study aimed to develop a novel eye movement protocol utilizing a smooth pursuit (SP) horizontal stimulus with velocity based on a sinusoidal wave. The primary objective was to assess the gain of eye movements in a cohort of healthy individuals and validate the findings against expected normal value. Methods: Seventeen healthy individuals, aged between 21 and 38 years were recruited and received smooth pursuit eye movements (SPEMs) recording binocularly, using Tobii Pro Fusion with 120 Hz of sampling rate to obtain normative data. To quantify the quality of eye tracking, gain (the ratio of eye movement velocity to stimulus velocity) was calculated for each participant. Findings: The calculated gain was 0.958±0.07, which was compared to the expected normal value of 0.935. This comparison served as a reliable validation criterion for the novel eye movement protocol. The results demonstrated that the developed protocol effectively quantified SPEMs (p=0.194), offering an accurate and reliable assessment of SP performance. Conclusion: Our study introduces a novel eye movement protocol, offering a valuable tool for investigating eye movement parameters. The significant findings in healthy individuals validate the effectiveness of the protocol in accurately assessing gain. Moreover, the potential implications of this research extend beyond the scope of healthy individuals, as it lays the groundwork for future investigations into the eye movement abnormalities in individuals with metabolic disorders. Understanding the relationship between metabolic health and eye movement parameters could lead to improved diagnostic and therapeutic approaches, benefiting patients with metabolic-related visual impairments and possibly providing novel biomarkers for assessing the metabolic status in clinical settings.