Prevalence of ametropia and visual impairment in elementary school students in Baoshan District of Shanghai / 中华实验眼科杂志

ABSTRACT

Background Epidemiologieal survey suggests that visual impairment in teenagers is a worldwide public health problem,and its leading cause is uncorrected refractive error.To conduct an extensive screening of visual impairment in teenagers and analyze the relevant affecting factors are significant works for the prevention and management of refractive errors.But high-quality epidemiological data on visual impairment and refractive error from large groups of children are lacking in Shanghai.Objective This study was to investigate the prevalence of ametropia and visual impairment in schoolchildren aged 6 to 12 years old.Methods In this cross-sectional study,4 686 students from 6 elementary schools in Baoshan District of Shanghai,a rural-urban fringe zone,China were selected by clustering sampling from May 2010 to April 2011.The eye examinations included visual acuity,ocular surface,ocular anterior segment,ocular media,fundus and intraocular pressure measurement,and the data autorefraction under cycloplegia and eye position were recorded.The cause of visual impairment was evaluated.Results A total of 4 594 students received examination with the response rate 98.0％,and autorefraction under cycloplegia was completed in 84.8％ schoolchildren (3 975/4 594).The prevalence rate of uncorrected visual acuity 0.5 or worse in both eyes was 14.4％ (662/4 594),with the wearing glasses rate 51.8％ (343/662).The percentage of students with the uncorrected visual acuity 0.5 or worse in at least one eye was 22.4％ (1 031/4 594).The prevalence rate of refractive error in the visual impaired students was 96.9％ (999/1 031),followed by amblyopia (37/1 031,3.6％).The prevalence rate of myopia,hyperopia,and astigmatic in the pupils after cycloplegia was 31.1％,4.3 ％ and 33.0％,respectively.In addition,the prevalence rate of myopia in public elementary schools was higher than that in migrant elementary schools (33.9％ versus 30.3％) (x2 =5.46,P =0.02).Logistic regression analysis showed that myopia was associated with age (OR =1.60,95 ％ CI1.53-1.68,P ＜ 0.01) and female (OR =1.33,95％ CI1.16-1.54,P＜0.01).Conclusions The leading cause of vision impairment is myopia in the elementary school students in Shanghai,China.The screening-ratio of refractive error and the coverage of refractive correction in the elementary school students in Shanghai are matters of urgent concern.