Visual Fatigue as a Predictor of Exercise Tolerance in Pediatric Athletes with Concussion

Abstract

Background:Concussion patients may manifest changes in exercise tolerance (ET). Since the visual system is affected as well, investigating the relationship between ET and vision could prove useful in developing better rehabilitation strategies.Hypothesis/Purpose:To explore trends between ET and visual fatigue in pediatric concussion patients.Methods:A Retrospective chart review of 63 pediatric concussion patients ages 12-21 was collected from 11/05/21 to 6/10/21. Each patient completed a validated symptom-related questionnaire resulting in quantitative clinical profile (CP) score (0-89) and ocular profile subtype (OPS) score (0-3) with higher scores indicating worse symptoms. The OPS score is a weighted score based off of 5 vision focused questions regarding visual symptoms and visual fatigue. Each patient was also evaluated by a physician and classified into an active rehabilitation (AR) step (Step 1-5) based on exertional testing results using heart rate to establish exertional threshold at the visit. Patients were split up into low ET level (n=10) who could not exceed HR<140bpm and high ET level (n=53) who exhibited vigorous to maximal intensities all tolerating HR>140bpm. Near point convergence (NPC) and other objective exam markers were also evaluated at each patient visit. A paired two sample t-test compared the differences in their OPS and objective clinical data.Results:The low ET group averaged an OPS score of 1.84, CP score of 43.20, and a physician measured average NPC of 9.96 cm, while the high ET group averaged an OPS score of 0.68, CP score of 13.87, and a physician measured NPC of 9.06 cm (Table 1). T-test for the OPS and CP score revealed statistically significant differences (p value of 4.04E-05 and 3.49E-06 respectively) while the t-test for NPC had a p-value of 0.491.Conclusion:Visual fatigue as endorsed by the OPS score may be a critical subjective marker in predicting ET in pediatric athletes after concussion. Those tolerating vigorous or maximal exertion generally had significantly lower OPS scores, despite similar NPC findings in this small sample. Further studies are required to confirm this trend and how it may affect exertional rehabilitation strategies.Table 1:Ocular Profile Score (OPS), Near Point Convergence (NPC), Clinical Profile Score (CPS) in low vs high exercise tolerance (ET) patients