Liwan Eye Study: the Fourth Follow-up

March 27, 2024 updated by: Zhongshan Ophthalmic Center, Sun Yat-sen University
Primary angle-closure glaucoma (PACG) is one of the major causes of blindness affecting more than 20 million patients worldwide. The goals of this observational cohort study are to investigate the 20-year incidence of PACG in Chinese population aged 50 years and to develop prediction models for the long-term risk of progression from primary angle-closure suspect (PACS) to PACG.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Primary angle-closure glaucoma (PACG) is potentially a devastating disease, responsible for half of glaucoma-related blindness worldwide, especially in East Asia. Primary angle-closure suspect (PACS), which is characterized by appositional angle closure, is the earliest stage of primary angle closure diseases and can finally progress to PACG. Thus, identifying PACS eyes at risk of angle closure is crucial for its management. However, the natural history of progression from PACS to PACG and its prediction models are still limited in long-term longitudinal studies. Meanwhile, visual impairment poses a significant global public health burden along with the accelerating trend of aging, it is imperative to further evaluate the visual impairment among the elderly population.

The Liwan Eye Study was a population-based study initiated in 2003. The decision to select Liwan District for the survey was taken because of its stable, older population and a socioeconomic profile representative of Guangzhou as a whole. At baseline, 1405 eligible subjects aged 50 years and older completed a comprehensive eye examination and a questionnaire interview regarding education, income, hypertension and diabetes mellitus. To improve the monitoring of PACS and prevent vision loss associated with PACG, the purposes of this observational cohort study are to investigate the 20-year incidence of PACG in Chinese population aged over 50 years, develop prediction models that include eye characteristics, demographic features, ocular imaging characteristics, and genetic factors for the long-term risk of progression from PACS to PACG. Moreover, we aim to investigate the 20-year change in visual impairment and associated factors.

Study Type

Observational

Enrollment (Estimated)

600

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

All participants who will be follow-up in this study are from the Liwan Eye Study. At baseline, study subjects were enrolled in Liwan District, Guangzhou. (Liwan District is 1 of 10 administrative districts in Guangzhou, with a population of 514,600.) The decision to select this district for the survey was taken because of its stable, older population and a socioeconomic profile representative of Guangzhou as a whole. Individuals aged 50 years or more who had been resident in the selected study districts for more than 6 months were considered eligible during the enumeration. A total of 1405 eligible subjects were identified from the register.

Description

Inclusion Criteria:

  • Participants who have previously participated in the Liwan Eye Study
  • Individuals who sign an informed consent form voluntarily

Exclusion Criteria:

  • None

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The 20-year incidence of primary angle-closure glaucoma (PACG) in Chinese population aged over 50 years
Time Frame: 20-year
The presence of PACG is determined by visual acuity, intraocular pressure, anterior segment optical coherence tomography (AS-OCT). The incidence of PACG is defined as the number of new cases of PACG divided by the number of individuals without PACG at baseline.
20-year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The development of prediction models for the long-term risk of progression from primary angle-closure suspect (PACS) to primary angle-closure glaucoma (PACG)
Time Frame: 5-year, 10-year, 20-year
Prediction model performance was assessed by discrimination and calibration.Discrimination was evaluated using the ROC curve and area under the curve (AUC) or C-statistics. Calibration was visualized through calibration plots and evaluated using the Hosmer-Lemeshow goodness-of-fit test (HL test).
5-year, 10-year, 20-year
The 20-year incidence of visual impairment in Chinese population aged over 50 years
Time Frame: 20-year
Visual acuity (VA) will be measured using the Early Treatment Diabetic Retinopathy Study (ETDRS) logMAR illiterate E VA chart. Visual impairment is defined as VA <20/60 & ≥20/400, and blindness is defined as VA<20/400 in the better-seeing eye.
20-year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Zhongshan Ophthalmic Center, Sun Yat-sen University

Investigators

  • Principal Investigator: Wei Wang, PhD, Zhongshan Ophthalmic Center, Sun Yat-sen University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

March 30, 2024

Primary Completion (Estimated)

September 30, 2024

Study Completion (Estimated)

September 30, 2024

Study Registration Dates

First Submitted

March 21, 2024

First Submitted That Met QC Criteria

March 21, 2024

First Posted (Actual)

March 27, 2024

Study Record Updates

Last Update Posted (Actual)

March 28, 2024

Last Update Submitted That Met QC Criteria

March 27, 2024

Last Verified

March 1, 2024

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2024KYPJ025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Available on request. The datasets generated from the current study will be available upon request from Dr Wei Wang (wangwei@gzzoc.com) after the study is completed.

IPD Sharing Access Criteria

For access to the data, please contact the principal investigator after the study is completed.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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