Objective Eye Tracking Deficits Following Concussion for Youth Seen in a Sports Medicine Setting

Abstract

Quantification of visual deficits may help to identify dysfunction following concussion. We evaluated eye-tracking measurements among adolescents within 10 days of concussion and healthy control participants. Patients who reported to 2 tertiary care sport concussion clinics within 10 days of concussion completed an objective eye tracking assessment. Seventy-nine participants completed the study, 44 with concussion (mean age = 14.1 ± 2.2 years, 39% female) and 35 controls (mean age = 14.3 ± 2.4 years, 57% female). Right eye skew along the bottom of the screen was significantly higher for the concussion group compared to controls (median = 0.022 [interquartile range = -0.263, 0.482] vs 0.377 [interquartile range = -0.574, -0.031]; P = .002), but not the left eye. Among the variables investigated, right eye skew was altered for adolescents with a concussion. Visual function is an important component in the postconcussion evaluation, and identifying deficits soon after injury may allow for earlier specialist referral and intervention.

The Measurement of Eye Movements in Mild Traumatic Brain Injury: A Structured Review of an Emerging Area

“…One study also reported a comparison of their smooth pursuit synchronization index outcome with a traditional measure of velocity error to validate their outcome measure (Contreras et al, 2011). One study used commercial software (Oculogica, Inc.) to process their data (Howell et al, 2018) and referred to several previous studies that had also used this software to suggest its validity. However, validity of the commercial software is unclear, as it should be noted that none of the studies that were referenced examined or reported the data processing involved.…”

“…Several studies (Maruta et al, 2010b;Contreras et al, 2011;Cifu et al, 2015;Diwakar et al, 2015;DiCesare et al, 2017;Wetzel et al, 2018;Stuart et al, 2019b) did provide some details regarding definitions but these substantially varied between the studies ( Table 2, Supplementary Table 1). Three studies provided no outcomes specific to traditional eye movements (Suh et al, 2006;Murray et al, 2014;Howell et al, 2018), but instead reported on novel outcomes of "Gaze Stabilization" (a fixation measure), "Eye Skew" (an asymmetry measure), and "Oculomotor error" (a smooth pursuit measure) that authors developed for their individual studies. Overall, reporting of possible eye movement outcomes from the eye-tracking devices substantially varied between studies.…”

“…None of the reviewed articles controlled for the impact of cognition or basic visual function (visual acuity or contrast sensitivity) on eye movements, and only one study (Stuart et al, 2019b) reported basic visual function scores. Many of the studies did not assess cognition and similarly many only reported that they excluded subjects based on visual function (i.e., eye chart screening or self-reported questionnaires) but provided no scores or results to verify this (Suh et al, 2006;DiCesare et al, 2017;Murray et al, 2017;Howell et al, 2018;Webb et al, 2018;Wetzel et al, 2018;Cochrane et al, 2019;Kelly et al, 2019). None of the studies provided any information on the use of corrective eye wear by the participants during the eye-tracking assessments, with several articles reporting that subjects had "normal or corrected to normal vision, " but it was unclear if individuals with vision correction were included in reported results.…”

“…There were a vast number of outcomes being recorded and reported, which ranged from relatively standard (e.g., prosaccades, anti-saccades, smooth pursuits etc.) to novel [e.g., eye skew (Howell et al, 2018), gaze stabilization (Murray et al, 2014), oculomotor error (Suh et al, 2006)] outcomes. Development and application of novel eye-movement outcomes may allow deficits to be uncovered that may otherwise not be found (Harezlak and Kasprowski, 2018).…”

“…We were surprised that only two studies (Maruta et al, 2010b(Maruta et al, , 2018) assessed for cognitive function and only one study reported data on visual function (Stuart et al, 2019b), with other studies only reporting that participants had "normal or corrected to normal vision" (Suh et al, 2006;DiCesare et al, 2017;Murray et al, 2017;Howell et al, 2018;Webb et al, 2018;Wetzel et al, 2018;Cochrane et al, 2019;Kelly et al, 2019). Eye-movements are underpinned by cognitive processes (Hutton, 2008;Mele and Federici, 2012), even from an early stage before the automatic bottom-up cascade of visual processing occurs (Baluch and Itti, 2011).…”