Skip to main content
OpenTrials
Recruiting

NCT Number: NCT05770661

China Axial Length Study

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.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Axial Length Child Development Eye Diseases Myopia Refractive Errors

Age range

3 year–18 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Shanghai Eye Disease Prevention & Treatment Center, Shanghai, Shanghai Municipality, China

Loading trial locations.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Primary outcomes

  1. Axial length

    Time frame: 2023-2026

    Axial length in millimeter was examined by IOL Master

Secondary outcomes

  1. Axial length elongation

    Time frame: 2023-2026

    The elongation in millimeter was the difference between two annual visits.

Other outcomes

  1. Comparison of visual acuity outcomes obtained by VA charts with different optotypes among children

    Time frame: Baseline vision testing at enrollment (single study visit)

    This outcome measure evaluates differences in uncorrected visual acuity (UCVA) results obtained using HOTV and Tumbling E logMAR charts among children aged 3-15 years.

Study contacts

Contact information is provided by the study sponsor or research team.

Xiangui He, PhD

CONTACT

[email protected]

15000755422 ext. 86

Xun Xu, MD

CONTACT

[email protected]

021-53555032 ext. 86

Sponsors and collaborators

Lead sponsor

Shanghai Eye Disease Prevention and Treatment Center

Other

Collaborators

  • Affiliated Hospital of Inner Mongolia Minzu University
  • First Affiliated Hospital of Guangxi Medical University
  • First Affiliated Hospital of Kunming Medical University
  • People's Hospital of Ningxia Hui Autonomous Region
  • Shandong University of Traditional Chinese Medicine
  • Sichuan Provincial People's Hospital
  • Tongji Hospital
  • Xinjiang Hospital of Traditional Chinese Medicine

Registry information

Official study title

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

Acronym: CALS

Important dates

Study start
2023
Primary completion
2026
Study completion
2026
First posted
Mar 15, 2023
Registry last updated
Dec 18, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.