Prevalence of Blindness, Visual Impairment in Chao Nan Area, China

NCT ID: NCT04143334

Last Updated: 2019-10-31

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Total Enrollment

3700 participants

Study Classification

OBSERVATIONAL

Study Start Date

2012-04-01

Study Completion Date

2016-12-01

Brief Summary

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This study will provide a profile of blindness/visual impairment, avoidable blindness and cataract surgery service in Chaonan, mainland China. We also evaluate the diagnostic accuracy of Rapid Assessment of Avoidable Blindness (RAAB) comparison with conventional survey.

Detailed Description

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This proposal describes a population-based study aimed at determining the prevalence of visual impairment, blindness and major causes in adults age 50 years old and above in Chaonan County of Guangdong province, where one of the Project Vision Charity Eye center was founded in 2009.

In the proposed study, we will examine 3700 Chaonan County residents aged 50 years and older, selected via a clustered, randomized sampling with probability proportional to size (PPS). The cluster will be at the village level, 50 subjects aged 50 years and older will be examined in each cluster includes Visual acuity, torch light, and fundus review, the major cause of blindness or visual impairment will be determined. We also randomly recruited 60% clusters,total 2250 participants, from RAAB survey to conduct a detailed conventional eye examination.

This study will provide a profile of blindness/visual impairment, avoidable blindness and cataract surgery service in Chaonan. we will evaluate the diagnostic accuracy of Rapid Assessment of Avoidable Blindness (RAAB) comparison with conventional survey. . It will provide important public health issues for the purposes of establishing a sustainable and suitable model to eliminate the cataract blindness in China.

Conditions

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Blindness Cataract Visual Impairment Refractive Errors

Keywords

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blindness cataract blindness diagnostic accuracy

Study Design

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Observational Model Type

OTHER

Study Time Perspective

CROSS_SECTIONAL

Study Groups

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RAAB survey

We will examine 3700 Chaonan County residents aged 50 years and older, selected via a clustered, randomized sampling with probability proportional to size (PPS). The cluster will be at the village level, 50 subjects aged 50 years and older will be examined in each cluster includes Visual acuity, torch light, and fundus review, the major cause of blindness or visual impairment will be determined.

Conventional survey

Intervention Type DIAGNOSTIC_TEST

conventional survey

All the recruited participants underwent ophthalmic examination according to the RAAB protocol and then 60% of them were re-examined with instruments in a mobile eye clinic set up in a village center on the same day. Examination in the mobile clinic included standardized visual acuity (VA) tests using logarithm of the minimum angle resolution charts, refraction, slit-lamp biomicroscopy, and dilated fundal examination with a binocular indirect ophthalmoscope.

Conventional survey

Intervention Type DIAGNOSTIC_TEST

Interventions

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Conventional survey

Intervention Type DIAGNOSTIC_TEST

Eligibility Criteria

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Inclusion Criteria

* aged 50 years and above
* In each household all persons , residing in the household for six months or more over the past year
* "Residing in the household" is defined as "sharing meals from the same kitchen with the other members of the household for at least 6 months in a year. Exclude any visitors.

Exclusion Criteria

* age \<50 years old
* Visitors in the villages
* Residing in the household\< 6 months
Minimum Eligible Age

50 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Chinese University of Hong Kong

OTHER

Sponsor Role lead

Responsible Party

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ZHANG XIUJUAN

Dr. Principal Investigator

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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XIUJUAN ZHANG, PhD

Role: PRINCIPAL_INVESTIGATOR

Chinese University of Hong Kong

References

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Li EY, Liu Y, Zhan X, Liang YB, Zhang X, Zheng C, Jhanji V, Xu P, Chang DF, Lam DS. Prevalence of blindness and outcomes of cataract surgery in Hainan Province in South China. Ophthalmology. 2013 Nov;120(11):2176-83. doi: 10.1016/j.ophtha.2013.04.003. Epub 2013 May 25.

Reference Type RESULT
PMID: 23714323 (View on PubMed)

Other Identifiers

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CRE-2011.389

Identifier Type: -

Identifier Source: org_study_id