China Axial Length Study
CALS
Axial Length Study of Children and Adolescents in Ten Provinces of China
1 other identifier
observational
30,000
1 country
2
Brief Summary
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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for all trials
Started Mar 2023
Typical duration for all trials
2 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
March 5, 2023
CompletedStudy Start
First participant enrolled
March 10, 2023
CompletedFirst Posted
Study publicly available on registry
March 15, 2023
CompletedPrimary Completion
Last participant's last visit for primary outcome
December 31, 2026
ExpectedStudy Completion
Last participant's last visit for all outcomes
December 31, 2026
December 18, 2025
December 1, 2025
3.8 years
March 5, 2023
December 11, 2025
Conditions
Outcome Measures
Primary Outcomes (1)
Axial length
Axial length in millimeter was examined by IOL Master
2023-2026
Secondary Outcomes (1)
Axial length elongation
2023-2026
Other Outcomes (1)
Comparison of visual acuity outcomes obtained by VA charts with different optotypes among children
Baseline vision testing at enrollment (single study visit)
Study Arms (2)
Myopes
To collect the ocular data among myopic children.
Non-myopes
To collect the ocular data among non-myopic children.
Eligibility Criteria
Students aged from 3 to 18 years old were recruited from schools to enroll the study.
You may qualify if:
- 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
You may not qualify if:
- Mental diseases, unable to cooperate to complete the eye assessment
- Ophthalmic diseases, inability to cooperate to complete the inspection
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- First Affiliated Hospital of Kunming Medical Universitycollaborator
- Shandong University of Traditional Chinese Medicinecollaborator
- People's Hospital of Ningxia Hui Autonomous Regioncollaborator
- The First Affiliated Hospital of Guangxi Traditional Chinese Medical Universitycollaborator
- Affiliated Hospital of Inner Mongolia Minzu Universitycollaborator
- Xinjiang Hospital of Traditional Chinese Medicinecollaborator
- Shanghai Eye Disease Prevention and Treatment Centerlead
- Tongji Hospitalcollaborator
- Sichuan Provincial People's Hospitalcollaborator
Study Sites (2)
Shanghai Eye Disease Prevention & Treatment Center
Shanghai, Shanghai Municipality, 200040, China
Shanghai Eye Disease Prevention and Treatment Center
Shanghai, China
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- observational
- Observational Model
- COHORT
- Time Perspective
- PROSPECTIVE
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Doctor
Study Record Dates
First Submitted
March 5, 2023
First Posted
March 15, 2023
Study Start
March 10, 2023
Primary Completion (Estimated)
December 31, 2026
Study Completion (Estimated)
December 31, 2026
Last Updated
December 18, 2025
Record last verified: 2025-12