Activity

Activity ID

7040

Expires

November 12, 2023

Format Type

Journal-based

CME Credit

1

Fee

$30

CME Provider: JAMA Ophthalmology

Description of CME Course
Abstract

Importance:
Concussion diagnosis remains clinical, without objective diagnostic tests available for adolescents. Known deficits in visual accommodation and autonomic function after concussion make the pupillary light reflex (PLR) a promising target as an objective physiological biomarker for concussion.

Objective:
To determine the potential utility of PLR metrics as physiological biomarkers for concussion.

Design, Setting, and Participants:
Prospective cohort of adolescent athletes between ages 12 and 18 years recruited between August 1, 2017, and December 31, 2018. The study took place at a specialty concussion program and private suburban high school and included healthy control individuals (n?=?134) and athletes with a diagnosis of sport-related concussion (SRC) (n?=?98). Analysis was completed June 30, 2020.

Exposures:
Sports-related concussion and pupillometry assessments.

Main Outcomes and Measures:
Pupillary light reflex metrics (maximum and minimum pupillary diameter, peak and average constriction/dilation velocity, percentage constriction, and time to 75% pupillary redilation [T75]).

Results:
Pupillary light reflex metrics of 134 healthy control individuals and 98 athletes with concussion were obtained a median of 12.0 days following injury (interquartile range [IQR], 5.0-18.0 days). Eight of 9 metrics were significantly greater among athletes with concussion after Bonferroni correction (maximum pupil diameter: 4.83 mm vs 4.01 mm; difference, 0.82; 99.44% CI, 0.53-1.11; minimum pupil diameter: 2.96 mm vs 2.63 mm; difference, 0.33; 99.4% CI, 0.18-0.48; percentage constriction: 38.23% vs 33.66%; difference, 4.57; 99.4% CI, 2.60-6.55; average constriction velocity: 3.08 mm/s vs 2.50 mm/s; difference, 0.58; 99.4% CI, 0.36-0.81; peak constriction velocity: 4.88 mm/s vs 3.91 mm/s; difference, 0.97; 99.4% CI, 0.63-1.31; average dilation velocity, 1.32 mm/s vs 1.22 mm/s; difference, 0.10; 99.4% CI, 0.00-0.20; peak dilation velocity: 1.83 mm/s vs 1.64 mm/s; difference, 0.19; 99.4% CI, 0.07-0.32; and T75: 1.81 seconds vs 1.51 seconds; difference, 0.30; 0.10-0.51). In exploratory analyses, sex-based differences were observed, with girls with concussion exhibiting longer T75 (1.96 seconds vs 1.63 seconds; difference, 0.33; 99.4% CI, 0.02-0.65). Among healthy control individuals, diminished PLR metrics (eg, smaller maximum pupil size 3.81 mm vs 4.22 mm; difference, -0.41; 99.4% CI, -0.77 to 0.05) were observed after exercise.

Conclusions and Relevance:
These findings suggest that enhancement of PLR metrics characterize acute adolescent concussion, while exercise produced smaller pupil sizes and overall slowing of PLR metrics, presumably associated with fatigue. Quantifiable measures of the PLR may serve in the future as objective physiologic biomarkers for concussion in the adolescent athlete.

Disclaimers

1. This activity is accredited by the American Medical Association.
2. This activity is free to AMA members.

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More Information
Commercial Support?
No

NOTE: If a Member Board has not deemed this activity for MOC approval as an accredited CME activity, this activity may count toward an ABMS Member Board’s general CME requirement. Please refer directly to your Member Board’s MOC Part II Lifelong Learning and Self-Assessment Program Requirements.

Educational Objectives

To determine the potential utility of pupillary light reflex metrics as physiological biomarkers for concussion.

Keywords

Emergency Medicine, Neurology, Neuro-ophthalmology, Ophthalmology, Traumatic Brain Injury

Competencies

Medical Knowledge

CME Credit Type

AMA PRA Category 1 Credit

DOI

10.1001/jamaophthalmol.2020.3466

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