Utility of iPhone-Based Pupillometry in Comparing Pupillary Dynamics Between Sport Concussed Subjects With Photosensitivity and Healthy Controls.

BACKGROUND

To compare the pupillary dynamics using an iPhone-based pupillometry technique in subjects with sports concussion with photosensitivity and aged-matched controls.

METHODS

Fifty subjects with sports concussion were compared with 50 aged-matched healthy controls. Athletes with persistent concussive symptoms for 1 year or more after the initial injury were included. All the subjects underwent a Post-Concussion Symptom Scale (PCSS) administration followed by pupillary dynamics measurement using an iPhone-based application (Reflex-Pro PLR analyzer).

RESULTS

The mean age was 27 ± 4 years in the concussed group and 26 ± 5 years in the control group. In subjects with concussion, there was a significant decrease in the mean of the following parameters: average constriction speed (1.10 ± 0.15 vs 1.78 ± 0.12 mm/s; P < 0.001), maximum constriction speed (2.05 ± 0.26 vs 3.84 ± 0.28 mm/s; P < 0.001), average diameter (3.64 ± 0.12 vs 0.36 ± 0.05 mm; P < 0.001), maximum diameter (4.75 ± 0.17 vs 5.23 ± 0.16 mm; P < 0.001), and minimum diameter (2.75 ± 0.17 vs 3.64 ± 0.11 mm; P < 0.001). An increase in the following parameters was noted in concussion vs age-matched controls: dilation release amplitude (0.54 ± 0.96 vs 0.36 ± 0.05 mm; P < 0.001) and latency (0.25 ± 0.05 vs 0.21 ± 0.02 s; P < 0.001). Subjects with concussion with photosensitivity exhibited increased dilation release amplitudes ( P < 0.001).

CONCLUSIONS

Individuals with sport concussion had impairment in pupillary constriction velocities, latency, and diameter in more than 1 year after concussion. The increase in dilation release amplitude among subjects with concussion might serve as a biomarker in diagnosing the underlying symptom of photosensitivity. The iPhone-based pupillometry could serve as a convenient and diagnostic tool in diagnosing these symptoms.