Developmental changes of normal pupil size and reactivity in children

Purpose: The goal of this study was to establish normative values for measurements of quantitative pupillometry in children. Methods: Quantitative pupillometry measurements were obtained from children between 1 and 18 years of age being seen for either a well child check or other outpatient appointment. Results: Maximum and minimum pupil size increased slightly with age; however, the correlation was weak (r = 0.29 and 0.19, respectively). Similarly weak correlations with age also were observed for maximum constriction velocity (r = -0.29) and dilation velocity (r = 0.27). Maximum (5.56 vs 4.97 mm) and minimum (3.74 vs 3.40 mm) pupil sizes were significantly larger in whites than in African Americans. Conclusions: Pupil size and reactivity show little correlation with age and are therefore suitable for further exploration in using pupillometry as a biomarker across the pediatric age range. Differences in race should be taken into consideration when pupillometry is used in mixed populations.