Adolescents with exercise-induced vision dysfunction have a 3-fold greater relative risk of developing persistent postconcussive symptoms

By Sravya Valiveti. This article was initially published in our Concussion Update newsletter; please consider subscribing.

Results from a recent study published in the Clinical Journal of Sports Medicine indicated that youth with exercise-induced vision dysfunction following sport-related concussion were at “a 3-folder greater risk” of developing persistent post-concussive symptoms (PPCS) compared to those without exercise-induced vision dysfunction. The authors set the criteria for exercise-induced vision dysfunction as ”reduced performance and/or symptom exacerbation on a post-exercise King-Devick (KD) test.” 

Researchers carried out a secondary analysis of randomized clinical trial data from three university-affiliated sports medicine programs. In the clinical trial, within ten days of sport-related concussion, the adolescents were given the KD test immediately before and 2 minutes after the Buffalo Concussion treadmill test was administered. The authors planned this pre- and post-exercise KD evaluation to identify adolescents who demonstrated exercise-induced vision dysfunction (distinct from any vision dysfunction participants may have exhibited at rest). 

For this study, Brian T. Vernau et al. assessed performance data from the ninety-nine adolescents with exercise-induced vision dysfunction to determine if exercise-induced vision dysfunction early after sport-related concussion was associated with developing PPCS. 

Final outcomes revealed that adolescents with exercise-induced vision dysfunction following injury were at a significantly higher risk of developing PPCS compared to those without dysfunction (71% vs. 34%), where exercise-induced vision dysfunction was associated with a relative risk of 3.13 for PPCS.