Other Clinical Trial - China Axial Length Study

Clinical Trial 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.

Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.

Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.

Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.

Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.

Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.

NCT number	NCT05770661
Study type	Observational
Source	Shanghai Eye Disease Prevention and Treatment Center
Contact	Xun Xu, MD
Phone	021-53555032
Email	drxuxun@sjtu.edu.cn
Status	Not yet recruiting
Phase
Start date	March 10, 2023
Completion date	June 30, 2025

China Axial Length Study — CALS

Clinical Trial Summary

Clinical Trial Description

Study Design