BlindnessNCT04143334
Prevalence of Blindness, Visual Impairment in Chao Nan Area, China
An observational study of Blindness and Cataract, run by Chinese University of Hong Kong.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 50 years and older
- Conditions the study is for
- Blindness, Cataract, Visual Impairment
- What is being tested?
- Conventional survey
- How many people
- 3,700 participants
- Where
- No sites listed yet
- Study dates
- 1 Apr 2012to 1 Dec 2016
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 years and older
- All sexes
- Adult, Older adult
Study population: Among the 3700 people, 169 (4.6%) could not be reached, 20 (0.5%) were unable to communicate, and 27 (0.7%) refused. Consequently, 3484 persons (response rate 94.2%) with a mean (±SD) age of 64.4±9.8 years were examined. These included 1397 men (40.1%) with an average age of 65.3 ±9.6 years and 2087 women (59.9%) with an average age of 63.8±9.8 years. Of the 2145 subjects (95.3%，2145/2250), 327 (15.2%) refused, and 2 (0.1%) were unable to cooperate for examination. Consequently, 1816 subjects (1816/2145, 84.7%) with a mean (±SD) age of 64.4±9.6 years received the conventional ophthalmic examination in the mobile eye clinic (figure 1). These included 686 men (37.8%) with an average age of 65.5±9.4 years and 1130 women (62.2%) with an average age of 63.8±9.6 years.
Who may be able to join
- 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.
Who cannot join
- age <50 years old
- Visitors in the villages
- Residing in the household< 6 months
About this study
Official title: Prevalence of Blindness, Visual Impairment and Main Avoidable Causes in Chao Nan Area
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.
Read the detailed description
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
- Blindness, Cataract, Visual Impairment, Refractive Errors
- Being tested
- Conventional survey
- Keywords
- blindness, cataract blindness, diagnostic accuracy
- Medical subject headings
- Blindness, Cataract, Vision Disorders, Refractive Errors
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Conventional surveyDiagnostic test
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: Diagnostic Test: Conventional survey | |
| 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. Receives: Diagnostic Test: Conventional survey |
What is being measured
The primary outcome is the main question the study is designed to answer.
the prevalence of blindness and visual impairment (VI) and main avoidable causes in Chaonan, China
the prevalence of blindness and visual impairment (VI), and report the avoidable causes, including cataract in Chaonan Region, Guangdong Province, southern China
Measured: one year
Secondary outcomes (1)
the diagnostic accuracy of RAAB
To evaluate the diagnostic accuracy of Rapid Assessment of Avoidable Blindness (RAAB)
Measured: one year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Oct 2019
- Study start1 Apr 2012
- Primary completion1 Dec 2015
- Study completion1 Dec 2016
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for BlindnessStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Cross-sectional
- Enrolment
- 3,700 participants (actual)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, ZHANG XIUJUAN, Chinese University of Hong Kong
- Investigators
- XIUJUAN ZHANG, PhD, Principal investigator, Chinese University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04143334
- Sponsor's protocol ID
- CRE-2011.389
- Status last verified
- Oct 2019
- First submitted
- 24 Oct 2019
- Last updated
- 31 Oct 2019
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
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.
PubMed 23714323
Study at a glance
From the registry record, last updated by the sponsor on 31 Oct 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prevalence of Blindness, Visual Impairment and Main Avoidable Causes in Chao Nan Area
- ClinicalTrials.gov ID
- NCT04143334
- Acronym / sponsor ID
- CRE-2011.389
- Conditions
- Blindness, Cataract, Visual Impairment, Refractive Errors
- Keywords
- blindness, cataract blindness, diagnostic accuracy
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 3,700 participants (actual)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 1 Apr 2012 (actual)
- Primary completion
- 1 Dec 2015 (actual)
- Study completion
- 1 Dec 2016 (actual)
- First posted
- 29 Oct 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
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.
Study design
- Observational model
- Other
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| RAAB survey | – | Diagnostic Test: Conventional surveyWe 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 | – | Diagnostic Test: Conventional surveyAll 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. |
Who may qualify
- Ages
- 50 years and older
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- Among the 3700 people, 169 (4.6%) could not be reached, 20 (0.5%) were unable to communicate, and 27 (0.7%) refused. Consequently, 3484 persons (response rate 94.2%) with a mean (±SD) age of 64.4±9.8 years were examined. These included 1397 men (40.1%) with an average age of 65.3 ±9.6 years and 2087 women (59.9%) with an average age of 63.8±9.8 years. Of the 2145 subjects (95.3%，2145/2250), 327 (15.2%) refused, and 2 (0.1%) were unable to cooperate for examination. Consequently, 1816 subjects (1816/2145, 84.7%) with a mean (±SD) age of 64.4±9.6 years received the conventional ophthalmic examination in the mobile eye clinic (figure 1). These included 686 men (37.8%) with an average age of 65.5±9.4 years and 1130 women (62.2%) with an average age of 63.8±9.6 years.
Key inclusion criteria (3 listed)
- 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.
Key exclusion criteria (3 listed)
- age <50 years old
- Visitors in the villages
- Residing in the household< 6 months
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Conventional survey | Diagnostic test | RAAB survey, conventional survey |
Primary outcome
the prevalence of blindness and visual impairment (VI) and main avoidable causes in Chaonan, China
Time frame: one year
the prevalence of blindness and visual impairment (VI), and report the avoidable causes, including cataract in Chaonan Region, Guangdong Province, southern China
1 secondary outcome
the diagnostic accuracy of RAAB
Time frame: one year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Oct 2019.
- Results publication: PubMed 23714323Li 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.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
XIUJUAN ZHANG, PhD principal investigator
Chinese University of Hong Kong
Questions about this trial
What is this clinical trial studying?
An observational study of Blindness and Cataract, run by Chinese University of Hong Kong.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 31 Oct 2019. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
the prevalence of blindness and visual impairment (VI) and main avoidable causes in Chaonan, China (time frame: one year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04143334, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 Oct 2019; AzTrials last refreshed its copy on 8 Nov 2026.