Developmental Changes of Normal Pupil Size and Reactivity in Children

The goal of this study was to establish normative values for measurements of quantitative pupillometry in children.

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.

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.

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.