China Axial Length Study (CALS)

Axial Length Study of Children and Adolescents in Ten Provinces of China

The primary objective of this multi-center, observational study is to establish the reference ranges of axial length in Chinese children and adolescents.

30,000 children aged 3-18 years were examined with cycloplegia to collect their ocular parameters and were all followed up for three years with annual visits.

Study Overview

• Status: Not yet recruiting
• Conditions: Axial Length, Children, China

• Study Type: Observational
• Enrollment (Anticipated): 30000

Contacts and Locations

• Study Contact: Name: Xun Xu, MD; Phone Number: 86 021-53555032; Email: drxuxun@sjtu.edu.cn
• Study Contact Backup: Name: Xiangui He, PhD; Phone Number: 86 15000755422; Email: xianhezi@163.com

Study Locations

• China
  • Shanghai
    • Shanghai, Shanghai, China, 200040
      • Shanghai Eye Disease Prevention & Treatment Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 3 years to 18 years (Child, Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Students aged from 3 to 18 years old were recruited from schools to enroll the study.

Description

Inclusion Criteria:

• Aged 3 to 18 years
• Have been lived in the research areas for at least one year, and will not move to other places in the following two years
• Parents or guardians sign an informed consent form, and children over 6 years old need oral consent to participate

Exclusion Criteria:

• Mental diseases, unable to cooperate to complete the eye assessment
• Ophthalmic diseases, inability to cooperate to complete the inspection

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Myopes; To collect the ocular data among myopic children.
Non-myopes; To collect the ocular data among non-myopic children.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Axial length	Axial length was examined by IOL Master	2023-2025

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Axial length elongation	The elongation was the difference between two annual visits.	2023-2025

Collaborators and Investigators

• Sponsor: Shanghai Eye Disease Prevention and Treatment Center
• Collaborators: Tongji Hospital; Sichuan Provincial People's Hospital; The Affiliated Hospital of Inner Mongolia Medical University; He Eye Hospital; The Second Affiliated Hospital of Fujian Medical University; People's Hospital of Ningxia Hui Autonomous Region; First Affiliated Hospital of Kunming Medical University; Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine; The First Affiliated Hospital of Guangxi Traditional Chinese Medical University

Study record dates

Study Major Dates

• Study Start (Anticipated): March 10, 2023
• Primary Completion (Anticipated): June 30, 2023
• Study Completion (Anticipated): June 30, 2025

Study Registration Dates

• First Submitted: March 5, 2023
• First Submitted That Met QC Criteria: March 5, 2023
• First Posted (Actual): March 15, 2023

Study Record Updates

• Last Update Posted (Actual): March 15, 2023
• Last Update Submitted That Met QC Criteria: March 5, 2023
• Last Verified: March 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: NO.CALS20220101

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No