Examining the inter -rater and inter-trial reliability of the NeuroOptics-3000 pupillometer to measure pupillary light response parameters

Research Objectives: To assess inter-rater and inter-trial reliability of the NeurOptics pupillary light response (PLR)-3000 pupillometer in measuring the pupillary light response parameters.

Design: Cross-sectional test-retest reliability study.

Setting: University laboratory.

Participants: Forty-eight healthy adults (age 18-40 y, 25 males, 23 females) without a history of neurological injury, optical surgery, or cognitive impairment.

Interventions: Two independent raters used the NeuroOptics PLR-3000 pupillometer to conduct 3 trials in the left and right eyes of each participant. The pupillometer provided a light stimulus (intensity:10 uW; background intensity: 0 uW, duration: 0.8s). In between trials, subjects rested for approximately 30 seconds-1 min, and in between raters, subjects rested for approximately 1-2 minutes.

Main Outcome Measures: Raters measured the initial pupil size (mm), end pupil size (mm), change in pupil size (%), latency (ms), average constriction velocity (m/s), maximum constriction velocity (m/s), average dilation velocity (m/s), and 75% recovery time (s). Data for the average and individual trials of each parameter were used to determine inter-rater and inter-trial reliability, respectively. Inter-rater and inter-trial reliability were evaluated using descriptive statistics, intraclass correlation coefficients (ICC), and the standard error of measurement.

Results: Initial pupil size, end pupil size, change in pupil size, average constriction velocity, maximum constriction velocity, and average dilation velocity all demonstrated good-to-excellent (ICC > 0.70) inter-rater and inter-trial reliability. The 75% recovery time parameter had fair inter-rater (ICC range 0.64-0.67) and poor inter-trial (ICC range 0.41-0.65) reliability.

Conclusions: The NeurOptics PLR-3000 is a reliable device to measure most PLR parameters. The PLR-3000 can be used to track the recovery of patients with neurological injuries, such as concussions. Further investigation is needed to understand the clinical usefulness of the 75% recovery time parameter.

Author(s) Disclosures: No disclosures.