Data regarding the epidemiology of reduced visual acuity (VA) among multiethnic children and adolescents in China are few. Understanding the vision-related health inequalities among different ethnic groups is crucial for health resource allocations and clinical managements for eye diseases.
We aim to determine the prevalence, main causes, and health inequalities of reduced VA in multiethnic school students in rural China.
A school-based eye survey including 7681 multiethnic school students aged 5 to 16 years in the southwestern part of China was conducted. Detailed ocular examinations including VA measurements, ocular motility evaluations, bilateral postcycloplegic refractions, and the assessments of the external eye, anterior segment, media, and retinal fundus were carried out by trained research vision professionals. Visual acuity was measured using a logarithm of the minimum angle of resolution E-chart, and reduced VA was defined as a presenting VA of worse than 20/40. Concentration index was initiatively utilized to measure health inequalities among different ethnic groups.
The prevalence of reduced VA was 11.4 per 100 children (95% confidence interval, 10.7 to 12.1%) based on the worse-seeing eye data. The prevalence of reduced VA increased with increasing age (P < .001 for trend) and was higher among girls compared with boys (P < .0001). Uncorrected refractive error was the principal cause for reduced VA, which accounted for 87.3% of the participants with reduced VA. The concentration index for reduced VA was 0.07 among different ethnic groups.
Compared with the estimates reported from previous studies on Chinese children and adolescents, a relatively lower prevalence of reduced VA was observed among multiethnic school students in rural China. Ethnic variations and health inequalities of reduced VA were not significant in this study.
1School of Public Health, Medical College of Soochow University, Suzhou, China
2Department of Ophthalmology, the Second People's Hospital of Yunnan Province, Kunming, China
3Department of Ophthalmology, the First Affiliated Hospital of Kunming Medical University, Kunming, China
4Department of Ophthalmology, Children's Hospital of Soochow University, Suzhou, China *email@example.com
Submitted: January 3, 2017
Accepted: July 11, 2017
Funding/Support: This work was supported by the National Natural Science Foundation of China (grants 81502824 and 81560169) and the High-level Personnel Training Program of Health and Family Planning in Yunnan Province (grant D-201666). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Conflict of Interest Disclosure: None of the authors have reported a conflict of interest.
Author Contributions: DJQ and MH contributed equally to the work presented here and therefore should be considered equivalent authors. Data Curation, Formal Analysis, Writing – Original Draft: DJQ; Data Curation, Investigation: MH; Funding Acquisition, Supervision, Validation: HZ; Writing – Review & Editing: QN; Data Curation, Funding Acquisition, Supervision: JL; Funding Acquisition: YY; Formal Analysis, Investigation, Supervision, Writing – Review & Editing: CWP.