Prevalence of astigmatism among 99,515 children in different areas of Xi'an City, China

To investigate the prevalence of astigmatism among children in different areas of Xi'an. A cross-sectional study was conducted in Xi'an, China, involving children from 139 primary schools, 28 junior high schools, and 10 senior high schools. Data on uncorrected visual acuity (UCVA) and non-cycloplegic spherical equivalent (SE) were collected from March 2023 to June 2023 based on a new screening model by the Department of Ophthalmology of Xi'an Central Hospital. Data from the right eye were included in the statistical analysis. Trend changes in astigmatism prevalence across different areas, educational stages, ages, and genders were analyzed using the X² test and trend test. A total of 99,515 children were included in the analysis. The overall prevalence of astigmatism was 59.3% [95% CI: 59.0% to 59.6%]. The prevalence of astigmatism was higher in urban areas compared to the urban-rural fringe (61.1% [95% CI: 60.6% to 61.6%] vs. 58.3% [95% CI: 57.9% to 58.7%]) (X²trend = 73.174, P < 0.05). Boys had a higher prevalence of astigmatism than girls (59.8% [95% CI: 59.4% to 60.2%] vs. 58.8% [95% CI: 58.6% to 59.0%]) (X²trend = 11.613, P < 0.05). Compared to the primary and senior school, the overall prevalence of astigmatism is most significant during the junior school stage (X²trend = 1710.133, P < 0.05), with rates of 54.6% in primary school, 71.3% in junior high school, and 68.7% in senior high school (X²trend = 10.694-868.913, P < 0.05), among which grade 9 has the highest prevalence (X²trend = 2766.194, P < 0.05). Myopia severity increased with the degree of astigmatism (X²trend = 2547.677, P < 0.05), and boys were more likely to experience worsening myopia with increasing astigmatism compared to girls (X²trend = 36.878, P < 0.05). Astigmatism was most prevalent among children in Xi'an during junior school, peaking in grade 9. Urban areas showed higher incidence rates than urban-rural ones, and boys had a consistently higher prevalence than girls, with WTR being the most common type.