Abstract
Purpose :
To assess the relationship between eye scanning parameters while walking and visual filed test statistics for patients diagnosed with visual field (VF) defects in a case series study.
Methods :
We developed a wearable head mounted platform equipped with an eye tracking system, a micro-PC, and a battery. The lightweight platform is capable of recording gaze parameters while walking in a comfortable manner. Fifteen patients with known VF defects participated in this study. All participants performed VF tests for both eyes with standard automated perimetry (SAP). Patients were asked to walk twice with the eye tracking platform in a validated obstacle track, as described in a previous work. We averaged the recorded gaze parameters over the two walking trials and performed Pearson’s linear correlation analysis with the three commonly reported VF testing indices: mean deviation (MD), pattern standard deviation (PSD), and the VF index (VFI). The best eye’s VF testing indices were included in the correlation assessment. We analyzed nine gaze parameters: number of fixations, fixations time rate, mean and variance of fixation locations, mean fixation period, number of saccades, saccades time rate, mean saccadic period, and mean saccadic amplitude.
Results :
The number of saccades and saccadic rate (in saccades per second) were determined to be linearly correlated with the MD and PSD statistics. However, VFI was not found to be correlated with any gaze parameter. Statistical testing showed a significant correlation between the number of saccades and MD (R = 0.56, P= 0.02, 95% CI: 0.10 to 0.83) and PSD values (R = 0.55, P= 0.03, 95% CI: 0.06 to 0.83). Additionally, saccadic rate linear correlation was significant with MD (R = 0.61, P= 0.01, 95% CI: 0.16 to 0.85) and PSD (R = 0.65, P= 0.01, 95% CI: 0.20 to 0.87). Correlation of the two saccadic parameters with MD and PSD values may suggest an association between rapid eye movements and the degree and irregularity of VF losses. However, we did not find statistical evidence showing that these two gaze parameters correlate with the amount of remaining function of the best eye of the participants, as the VFI was not significantly correlated with the gaze parameters (P>0.05).
Conclusions :
Number of eye saccades and saccadic time rate while walking showed a possible association with the degree and irregularity of VF losses as represented by MD and PSD statistics.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.