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This study aimed to identify when and how eye movements change across the human lifespan to benchmark developmental biomarkers. The sample size comprised 45,696 participants, ranging in age from 6 to 80 years old (M = 30.39; SD = 17.46). Participants completed six eye movement tests: Circular Smooth Pursuit, Horizontal Smooth Pursuit, Vertical Smooth Pursuit, Horizontal Saccades, Vertical Saccades, and Fixation Stability. These tests examined all four major eye movements (fixations, saccades, pursuits, and vergence) using 89 eye-tracking algorithms. A semi-supervised, self-training, machine learning classifier was used to group the data into age ranges. This classifier resulted in 12 age groups: 6-7, 8-11, 12-14, 15-25, 26-31, 32-38, 39-45, 46-53, 54-60, 61-68, 69-76, and 77-80 years. To provide a descriptive indication of the strength of the self-training classifier, a series of multiple analyses of variance (MANOVA) were conducted on the multivariate effect of the age groups by test set. Each MANOVA revealed a significant multivariate effect on age groups (p < 0.001). Developmental changes in eye movements across age categories were identified. Specifically, similarities were observed between very young and elderly individuals. Middle-aged individuals (30s) generally showed the best eye movement metrics. Clinicians and researchers may use the findings from this study to inform decision-making on patients' health and wellness and guide effective research methodologies.
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AIM: Neural deficits were measured via the eye tracking of vertical smooth pursuit (VSP) as markers of traumatic brain injury (TBI). The present study evaluated the ability of the eye tracking tests to differentiate between different levels of TBI severity and healthy controls. METHODOLOGY: Ninety-two individuals divided into four groups (those with mild, moderate or severe TBI and healthy controls) participated in a computerized test of VSP eye movement using a remote eye tracker. RESULTS: The VSP eye tracking test was able to distinguish between severe and moderate levels of TBI but unable to detect differences in the performance of participants with mild TBI and healthy controls. CONCLUSION: The eye-tracking technology used to measure VSP eye movements is able to provide a timely and objective method of differentiating between individuals with moderate and severe levels of TBI.
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AIM: Eye tracking tests to measure horizontal and vertical saccades as a proxy for neural deficits associated with traumatic brain injury (TBI) were evaluated in the present study. METHODOLOGY: A total of 287 participants reporting either no TBI, mild, moderate or severe TBI participated in a suite of eye tracking tests to measure horizontal and vertical saccadic performance. RESULTS: The horizontal saccades test offered a sensitivity of 0.77 and a specificity of 0.78, similarly the vertical saccades tests offered a sensitivity of 0.64 and a specificity of 0.65. CONCLUSION: The results indicated that using eye-tracking technology to measure these metrics offers an objective, reliable and quantifiable way of differentiating between individuals with different severities of TBI, and those without a TBI.
RESUMEN
PURPOSE: The purpose of this study was to determine the reliability of interpupillary distance (IPD) and pupil diameter (PD) measures using an infrared eye tracker and central point stimuli. Validity of the test compared to known clinical tools was determined, and normative data was established against which individuals can measure themselves. METHODS: Participants (416) across various demographics were examined for normative data. Of these, 50 were examined for reliability and validity. Validity for IPD measured the test (RightEye IPD/PD) against the PL850 Pupilometer and the Essilor Digital CRP. For PD, the test was measured against the Rosenbaum Pocket Vision Screener (RPVS). Reliability was analyzed with intraclass correlation coefficients (ICC) between trials with Cronbach's alpha (CA) and the standard error of measurement for each ICC. Convergent validity was investigated by calculating the bivariate correlation coefficient. RESULTS: Reliability results were strong (CA > 0.7) for all measures. High positive significant correlations were found between the RightEye IPD test and the PL850 Pupilometer (P < 0.001) and Essilor Digital CRP (P < 0.001) and for the RightEye PD test and the RPVS (P < 0.001). CONCLUSIONS: Using infrared eye tracking and the RightEye IPD/PD test stimuli, reliable and accurate measures of IPD and PD were found. Results from normative data showed an adequate comparison for people with normal vision development. TRANSLATIONAL RELEVANCE: Results revealed a central point of fixation may remove variability in examining PD reliably using infrared eye tracking when consistent environmental and experimental procedures are conducted.