The study was done to evaluate the prevalence, incidence and their related risk factors of strabismus among preschool children in China.

Children born in Yuhuatai District of Nanjing were invited to participate in the Nanjing Eye Study for a comprehensive eye examination annually since 2015. The data presented in this paper were obtained from 2015 to 2017, when these children grew from the age of 3 to 5 years.

2018 children of 2300 eligible preschoolers completed the baseline eye examination when they were 3 years old. Among the 2018 participants, 50 had strabismus. In multivariable analysis, prevalent strabismus was independently associated with parental strabismus history, hyperopia, prematurity and astigmatism. Among 1766 children followed up for 2 years, 63 developed strabismus , of whom 57 had exotropia and 6 had esotropia. In multivariable analysis, incident strabismus was significantly associated with parental strabismus history (OR=5.55, p=0.04) and prematurity.

The study concluded that higher incidence of strabismus and a higher exotropia:esotropia ratio than previous studies in preschool children. Parental strabismus history and prematurity were associated with a higher risk for both prevalent and incident strabismus.