Pupillary measurements and anisocoria in Chinese preschoolers 3-4 years of age screened using the plusoptiX A12C.

PURPOSE: To evaluate the distribution of the pupil diameter and distance and the incidence of anisocoria in a screening setting for Chinese preschoolers 3-4 years of age.

METHODS: This was a cross-sectional, population-based study conducted in children aged 3-4 years in Nanjing, China. Plusoptix photoscreening was conducted without cycloplegia. Additional assessments were conducted, including light reaction test, reevaluation for anisocoria (in dim and bright light), swinging-flashlight test, and cocaine test, if necessary.

RESULTS: A total of 1,818 children were screened. Pupillary measurements were conducted successfully in nearly all children (99.3% for the pupil diameter; 98.4% for the interpupillary distance). The pupil diameters of both eyes of each individual were highly correlated (5.9 ± 0.7 mm in both eyes; P < 0.0001; r = 0.93). The mean interpupillary distance was 50.1 ± 3.1 mm. The pupil diameters (6.0 mm in boys; 5.8 mm in girls) and interpupillary distance (50.6 mm in boys; 49.5 mm in girls) were correlated with sex (all P < 0.0001) but not age (P = 0.22; P = 0.68). General anisocoria of 0.5-0.9 mm in 7.8% of children and 1.0-1.2 mm in 0.4% of children was found. No child was diagnosed with pathological anisocoria, craniofacial trauma, or congenital malformation syndrome.

CONCLUSIONS: The Plusoptix photoscreener is a useful tool for obtaining pupillary measurements and detecting anisocoria in a screening setting. For Chinese preschoolers 3-4 years of age the mean pupil diameter and distance were 5.9 and 50.1 mm, respectively, with sex-related difference; anisocoria of 0.5-0.9 mm is present in 7.8% of children.