# A Comparison of Quantitative Pupillometry and VOMS in Division 1 Female Soccer Players

## TL;DR

This study compares two tools for assessing brain function in female soccer players and finds they measure different things.

## Contribution

The study reveals that quantitative pupillometry and VOMS assess different constructs in concussion evaluation.

## Key findings

- 11.5% of athletes had abnormal baseline pupillometry results.
- NPi scores did not correlate with VOMS scores, suggesting different constructs are measured.
- Athletes with lower NPi scores had reduced pupil constriction and larger minimum pupil size.

## Abstract

Background and Objectives: Vision uses about half of the pathways within the brain, and these anatomical structures are susceptible to injury in concussion. Authors have suggested that subconcussive head impacts, common in soccer, may disrupt visual function. The following study aimed to explore and compare quantitative pupillometry and Vestibular Ocular Motor Screening (VOMS) in female soccer athletes. Materials and Methods: Twenty-six Division 1 female soccer athletes (20.46 ± 2.36 years) received baseline quantitative pupillometry and VOMS measurements. Results: Of the 26 tested athletes, 3 (11.5%) had clinically significant pupillometry findings at baseline. The mean Neurological Pupil Index or NPi, a composite generated from pupillometry, did not vary: 3.9 ± 0.4 (right eye) and 4.0 ± 0.4 (left eye). No difference in NPi was observed compared to the VOMS score (p > 0.05). Kruskal–Wallis H tests were significant in the right eye for constriction percentage (χ2(2) = 17.843, p < 0.001, E2 = 0.69) and minimum pupil size (χ2(2) = 7.976, p = 0.019, E2 = 0.31). A post hoc Dunn test showed significant differences in constriction percentage and minimum pupil size between low NPi and high NPi groups (p < 0.05). One athlete sustained a concussion. NPi was measured within 24 h and was normal, but VOMS was not (total score = 4). Conclusions: The components of pupillometry need more investigation, and there is a need for agreement on concussion-specific cutoffs for quantitative pupillometry for concussion assessment. The lack of a relationship between quantitative pupillometry and VOMS suggests that these tools evaluate different constructs. Athletes with an NPi < 3.8 had significantly less constriction percentage and larger minimum pupil size than athletes with higher NPi scores. More research should be carried out to determine the usefulness of the NPi score, and perhaps researchers should consider individual pupillometry components.