Objective To assess the test-retest reliability and the sensitivity/specificity of smooth pursuit assessments using a commercially available product (EYE-SYNC®) that records eye-tracking as radial and tangential variance while the athlete wears a google device.

Design Prospective, case-control.

Setting Three NCAA Division I universities.

Participants Varsity athletes.

Interventions (or Assessment of Risk Factors) Athletes were given a preseason baseline test of smooth pursuits using EYE-SYNC®. When an athlete presented acutely with a suspected concussion, (sideline or within 24 hours) a battery of tests were performed including the EYE-SYNC® smooth pursuits. If a concussion was clinically diagnosed, a teammate control was identified based on co-morbid conditions (attention deficit disorder, learning disability, migraine headache disorder, mood disorder) and school year and the EYE-SYNC® smooth pursuit test was performed.

Outcome Measures EYE-SYNC® smooth pursuit test.

Main Results Baseline and post-injury data were collected on 33 concussed athletes and 33 matched-controls. Athlete were predominantly male (24, 73%) with a sport distribution of football (18, 55%), softball (6, 18%), women’s/men’s basketball (2 each, 6%), women’s basketball, cheer, baseball (2 each, 6%), volleyball, women’s/men’s soccer, gymnastics, baseball (1 each,3%). The test-retest reliability (ICC) for tangential variability was 0.71 and radial variability 0.47 (average 363.3 days between assessments). The sensitivity and specificity for any increase in tangential variability was 48%/58%, and any increase in radial variability was 52%/61%.

Conclusions Change in tangential variability, but not radial, on EYE-SYNC® smooth pursuits has fair test-retest reliability but neither should be used in isolation to diagnose concussion.