Objective Eye Tracking Metrics of Vision and Autonomic Dysfunction Distinguish Adolescents With Acute Concussion and Those with Persistent Post-Concussion Symptoms from Uninjured Controls

Abstract

To explore the utility of an eye-tracking assessment in distinguishing binocular alignment, saccadic movement, and pupillary dynamics among uninjured adolescents, acute cases (= 28 days since concussion), and persistent cases (>28 days since concussion). Visual and autonomic system disturbances are common sequelae of concussion. Quantification of visual and autonomic dysfunction via an eye tracking device could provide an objective method of acute diagnosis and subacute identification of ongoing injury. We compared 347 eye tracking metrics, derived from a 220 seconds eye-tracking assessment, among 132 uninjured adolescents (mean age: 15.3, 56.2% female), 110 acute cases (mean days since injury: 12.5, mean age: 15.4, 46.4% female), and 95 persistent cases (mean days since injury: 53.6, mean age: 15.4, 70.2% female) using Kruskal-Wallis tests with Bonferroni corrections to account for multiple comparisons. Nine eye-tracking metrics were significantly associated with injury status. One measure of binocular alignment (acute v. control: p = 0.003, persistent v. control: p = 0.001) and one measure of saccadic movement (acute v. persistent: p = 0.03, acute v. control: p = 0.03, persistent v. control: p < 0.001) were worse in cases. Cases had larger left and right mean and median pupil size than uninjured adolescents (acute v. control, p < 0.001; persistent v. control, p < 0.001). Cases had greater differences in mean (acute v. control: p < 0.001, persistent v. control: p < 0.001), median (acute v. control, p < 0.001, persistent v. control, p = 0.003), and variance of (acute v. control: p < 0.001, persistent v. control: p < 0.001) left and right pupil size. Eight of these metrics distinguished female cases from uninjured adolescents, but similar differences were not observed in male participants. Objective eye tracking technology can identify vision and pupillary disturbances after concussion. These metrics could be integrated into clinical practice to monitor recovery in a heterogeneous adolescent concussion population and may identify sex-specific differences in autonomic dysfunction.