Effect of Increasing Time Spent Outdoors on Myopia Prevention in School-Aged Children in Northeast China

Not Applicable

Completed

• Conditions: Myopia

• Registration Number: NCT02271373
• Lead Sponsor: Anhui Medical University

Brief Summary

The purpose of this study is to develop a school-based intervention aimed at prevent the onset and development of myopia among school aged children by increasing time spent outdoors in northeast China.

Detailed Description

The purpose of this study is to develop a school-based intervention aimed at prevent the onset and development of myopia among school aged children by increasing time spent outdoors among elementary and secondary school students in northeast China. It is expected that the results will provide evidences for policy-makers and school healthcare providers for their school children myopia prevention.

Study Timeline

• Study Start: 2012-11
• Primary Completion: 2013-11
• Study Completion: 2014-02
• Status Verified: 2014-10
• Study First Submitted: 2014-10-19
• Study First Submitted QC: 2014-10-21
• Study First Posted: 2014-10-22
• Last Update Submitted: 2014-10-22
• Last Update Posted: 2014-10-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 3521

Inclusion Criteria

• Grade of 1 to 5 in elementary schools and grade of 7 to 8 in secondary schools.

Exclusion Criteria

• Visual defect or other eye diseases; wearing orthokeratology; refractive surgery history.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Changes in uncorrected visual acuity	Baseline, Month 6, Month 12	Uncorrected visual acuity (UCVA) was measured for the right eye, then the left eye, with a E Standard Logarithm Vision Acuity Chart (GB11533-2011) in 5-grade notation (5- LogMAR), with illumination of the chart around 500lx. If one of the eyes UCVA was less than 5.0, then tests with combined lenses were conducted among the poor eye-sighted for confirming the types of ametropia (normal, myopia, hyperopia or other eye diseases)．All the measurements were recorded.

Secondary Outcome Measures

Name	Time	Method
Questionnaire survey	Baseline	The parents and children underwent an interview together. The questionnaire included questions on children's gender, ethnicity, region of habitation; questions on parental education level, the monthly family income and whether the parents were myopic or not;. The interview also included questions on the amount of time spent for learning (reading or writing), screen time (television, computer, etc) and time spent outdoors after school in recent 7 days.
Changes in ocular biometric parameters	Baseline, Month 12	A random subsample (12.8%) underwent cycloplegia. After ensuring that there was no risk for a medical mydriasis, cycloplegia was performed at baseline and intervention after 1 year in the Shenyang Aier Ophthalmology Hospital, respectively. Ocular biometric parameters (axial length, corneal curvature, anterior chamber depth and IOP) were measured in both eyes of all participants. Axial length, corneal curvature and anterior chamber depth were measured with IOL Master (intraoeular len master, IOL. Master) (Carl Zeiss Meditex, Jena, Germany); Intraocular pressure (IOP) measurement was obtained using a non-contact tonometry (NT-510, NIDEK, Gamagori, Japan). Cycloplegia was achieved by 0.5% tropicamide eye drops. Six drops of tropicamide 0.5% were administered at 5-minute intervals for both eyes. Refractometry was performed 20 minutes after the last cycle of cycloplegic eye drops by retinoscopy (YZ-24, Suzhou, China).