Novel eye-tracking metrics can help properly identify concussion-related vision disorders

In a new study led by Children's Hospital of Philadelphia (CHOP), researchers found that novel eye-tracking metrics can help properly identify concussion-related vision disorders, a common phenomenon among patients with persisting post-concussive symptoms that last more than 28 days after their initial injury. The findings, recently published in the Journal of Sport and Health Science, suggest that objective infrared eye tracking could help identify which patients would benefit the most from referrals to and treatment from concussion specialists.

Almost two million pediatric concussions occur every year in the United States. While most children report their concussion symptoms resolving within the first 28 days after injury, up to 30% of children have persisting post-concussive symptoms, which can impact both school performance and physical activity. Early identification of concussion-related vision disorders – causing symptoms of blurred or double vision, eye strain, or headaches – is critical for improving outcomes.

Prior research demonstrated that a clinical visio–vestibular examination (VVE) – a series of brief eye movement and balance assessments intended to identify deficits in visual and vestibular function – and infrared eye tracking may provide helpful data that can help clinicians diagnose concussion.

A comprehensive vision examination by an eyecare professional remains the basis for making the diagnosis for a concussion-related vision disorders, which might be missed during a typical concussion evaluation. The earlier we can identify these vision disorders through easy-to-use objective means, the earlier we can refer patients to specialists to get a proper diagnosis and start receiving more specialized treatment."

Christina L. Master, MD, senior study author, sports medicine specialist and co-director of the Minds Matter Concussion Program at CHOP

This prospective study enrolled 108 adolescents whose concussion symptoms persisted beyond 28 days after initial injury. The patients were evaluated with VVE, comprehensive vision examination, and an eye tracking device. Of those enrolled, 67 (62%) were diagnosed with a concussion-related vision disorder by a comprehensive vision examination, with the most common diagnosis being convergence insufficiency, which can cause double vision and visual fatigue when looking at things up close in tasks such as reading.

The study also utilized EyeBOX, which measures and records the gaze positions across five 40-s cycles while the subject watches a video. Higher BOX scores indicate a greater likelihood of concussion. The study found that the average BOX score was significantly higher for patients with concussion-related vision disorders compared with patients who did not have vision disorders (8.1 ± 5.8 vs. 5.2 ± 4.1; p = 0.007). The study found that for each 1-point increase in the BOX score, the odds of a patient experiencing a concussion-related vision disorder was 15% higher.

"Our study strongly suggests that eye-tracking technology could significantly augment current clinical concussion evaluations, ensuring that patients with ongoing vision symptoms are identified promptly and are referred for rehabilitation for their concussion-related vision disorder," Master said.

This study was supported by National Institute of Neurological Disorders and Stroke grant 1R41NS103698-01A1.