Stereoacuity and Related Factors in Healthy Preschool Children: the Nanjing Eye Study.

Purpose: To assess the distribution of stereoacuity and related factors in healthy preschool children aged 48-60 months in eastern China. Methods: This cross-sectional study was part of the Nanjing Eye Study, a longitudinal population-based cohort study. In 2016, preschool children without any neurological problems or ophthalmological abnormalities completed comprehensive eye examinations, including visual acuity, ocular alignment and movements, cycloplegic refraction, axial length, interpupillary distance, Titmus stereotest, anterior segment, and fundus examination. Multivariate linear regression model was used to determine the factors associated with stereoacuity score, and logistic regression model was used to determine the factors associated with subnormal stereoacuity (worse than 40 arc-seconds). Results: Among 942 healthy preschool children (mean age = 55 months), the mean (SD) stereoacuity was 81 (2.3) arc-seconds with majority (76.5%) worse than 40 arc-seconds. In the multivariate analysis, older age (p = 0.001) and better presenting visual acuity (PVA) (p = 0.01) were independently associated with better stereoacuity score. Older age was also associated with low risk of subnormal stereoacuity (odds ratio = 0.37,p < 0.001 for age 57-60 months compared to age 48-51 months). Conclusions: The maturation of stereopsis has not completed by the age of 48-60 months. Age and PVA should be taken into account when evaluating stereopsis in healthy preschoolers. The significant associations of age and PVA with stereoacuity provide valuable insights into possible intervention for healthy preschool children with poor stereoacuity.