The Distribution of Astigmatism in Children and Adolescents in Wenzhou Area and Risk Factor Analysis

Abstract

Objective: To evaluate the distribution of astigmatism in children and adolescents in the Wenzhou area and determine the correlation of astigmatism with related risk factors, such as parents’ astigmatism, age, gender, and body mass index (BMI). Methods: This was a cross-sectional study conducted in cooperation with the Eye Hospital and the Second Affiliated Hospital of Wenzhou Medical University. Subjects came from the Children’s Health Examination Center of the Second Affiliated Hospital of Wenzhou Medical University, from September 2011 to March 2016. Ophthalmology exams included entrance tests (visual acuity, pupil reaction, extraocular muscles, etc.) and cycloplegic refraction. Each child’s height, weight, bust, waist, and hips were also measured. For this study, astigmatism was considered when the cylinder was higher than or equal to 0.5 diopter (D) in the right eye. The non-cycloplegic refractive status of the parents were measured for further analysis. Rank sum test, chi-square test and logistic regression analysis were used to analyze the distribution of astigmatism in children and adolescents and its risk factors. Results: A total of 525 subjects were examined, and 83.4% (438/525) completed the study. The prevalence of astigmatism was 59.4% (260). The percent of subjects with astigmatism between 0.50 D and 1.00 D was 80.8%, and the percent between 1.25 D and 2.00 D was 11.2%. The percent with astigmatism higher than 2.00 D was 8.1%. Obese children tended to have a higher prevalence of astigmatism (χ2=6.347, P=0.042) compared with non-obese children. With the rule (WTR) astigmatism was predominant (73.8%), and there was no significant difference in the astigmatism axis distribution between males and females (χ2=3.104, P=0.212) or among the different age groups (χ2=10.578, P=0.102). In the analysis of risk factors, the prevalence of astigmatism was higher in children with at least one astigmatic parent (χ2=7.484, P=0.024) compared with the children without an astigmatic parent. Logistic regression analysis indicated that the main factor that influenced the development of children and adolescents's astigmatism was the cylinder of mother (odds ratio=2.2, 95% confidence interval: 1.1-4.4, P=0.023). Conclusions: The prevalence of astigmatism in children and adolescents was 59.4% in Wenzhou area, and WTR was predominant. The astigmatism of the mother may increase the risk of astigmatism in children and adolescents. Key words: Keywords: children and adolescents; astigmatism; parental astigmatism; obesity