Prevalence and patterns of subnormal visual acuity and refractive errors among preschool children in Sucheng district: a cross-sectional study.

Objective: To investigate the visual acuity and refractive status of preschool children in the Sucheng District of Suqian city and analyze the incidence and distribution patterns of visual and refractive abnormalities in this district METHODS: This cross-sectional study was conducted from April to June 2024 and involved 27,062 children from 61 kindergartens in the district. Standard logarithmic visual acuity charts and the Spot VS100 binocular refractive screener were used to assess visual acuity and noncycloplegic refractive status. Chi-square tests and trend tests were employed to analyze differences in visual acuity and refractive status across age groups.

Results: Median visual acuity improved from 0.63 (3-year-olds) to 0.80 (6-year-olds). The overall prevalence of subnormal visual acuity was 12.4%, with a significantly higher rate observed in male participants (13.1%) than in female participants (11.5%, P<0.001). The total detection rate of refractive abnormalities was 13.02%. While the proportion of simple myopia tended to increase (χ²=33.15, P<0.001), the proportions of simple hyperopia, mixed astigmatism, and compound myopic astigmatism decreased with age (χ²=11.32, 6.84, 4.57; P<0.05). Although the proportion of emmetropia increased with age (84.41% to 88.15%), this trend was not statistically significant (P=0.121).

Conclusion: This cross-sectional study suggests an association between older age and lower detection rates of overall refractive abnormalities, alongside rising simple myopia prevalence. However, these findings require longitudinal confirmation to distinguish true developmental trends from cohort effects.