Determinants of the onset and progression of diabetic retinopathy in south China: Guangzhou Diabetic Eye Study

ISRCTN ISRCTN15853192
DOI https://doi.org/10.1186/ISRCTN15853192
Secondary identifying numbers NOPE-2019-0244.R1
Submission date
20/03/2020
Registration date
13/04/2020
Last edited
02/07/2025
Recruitment status
No longer recruiting
Overall study status
Ongoing
Condition category
Eye Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
Diabetic retinopathy is a diabetes complication that affects the eyes. The incidence and risk factors for diabetic retinopathy in southern China remain unclear. This study aims to explore the onset and progression of diabetic retinopathy and its determinants in South China.

Who can participate?
Type 2 diabetic patients registered in community health centres in Yuexiu district in Guangzhou, China

What does the study involve?
Comprehensive eye tests are performed annually for 5 years, as well as blood and urine tests.

What are the possible benefits and risks of participating?
Participants receive an annual comprehensive eye test and one-on-one ophthalmologist consultation based on the exam results. All the exams follow the normal clinical operation.

Where is the study run from?
Zhongshan Ophthalmic Center, Sun Yat-sen University (China)

When is the study starting and how long is it expected to run for?
November 2017 to October 2025

Who is funding the study?
National Natural Science Foundation of China

Who is the main contact?
Prof. Wenyong Huang
hweny@mail.sysu.edu.cn

Contact information

Dr Wei Wang
Scientific

No. 54. Xianlie Nan Road
Yuexiu District
Guanghzou
510000
China

Phone +86 (0)20 87334687
Email wangwei@gzzoc.com
Ms Yuting Li
Scientific

No. 54. Xianlie Nan Road
Yuexiu District
Guangzhou
510000
China

Phone +86 (0)20 87334687
Email liyuting@gzzoc.com

Study information

Study designCommunity-based prospective cohort study
Primary study designObservational
Secondary study designCohort study
Study setting(s)Community
Study typeScreening
Participant information sheet Not available in web format, please use the contact details to request a participant information sheet
Scientific titleGuangzhou Diabetic Eye Study (GDES): exploring the onset and progression of diabetic retinopathy and the determinants in south China: a prospective cohort study
Study acronymGDES
Study objectivesThis project aims to explore the onset and progression of diabetic retinopathy (DR) and their determinants through a prospective cohort in South China.
Ethics approval(s)Approved 25/10/2017, Zhongshan Ophthalmic Center Ethics Committee, Sun Yat-sen University (No.7 Jinsui Road, Zhujiang New Town, Guangzhou, China; +86 (0)20 87332529; zocethics@163.com), ref: 2017KYPJ094
Health condition(s) or problem(s) studiedDiabetic retinopathy screening among people with diabetes
InterventionThe GDES is an ongoing community-based prospective cohort study that includes type 2 diabetic patients registered in the community health centres in Yuexiu district in Guangzhou. This district is one of the oldest and central areas of Guangzhou, the population is stable. The Zhongshan ophthalmic centre (ZOC), which is affiliated with Sun Yat-sen University in Guangzhou, is located in this district and is the main provider of eye health services for the city. The communities are stable and the community health centres have established long-term collaboration with ZOC and are fully equipped with a well-established registry system for diabetic patients. The participants were originally recruited in November 2017, and the plan was to follow up on them annually for 5 years. All ocular examinations were performed at ZOC. The examinations are as follows:
1. Visual acuity and refraction tests performed by qualified optometrists
2. Ocular biometric measurements
3. Intraocular pressure (IOP) measurement
4. Pupil dilation
5. Refraction
6. Slit lamp and fundus examinations
7. Colour retinal photographs
8. Optical coherence tomography (OCT)
9. Questionnaire interview
10. Biological sample collection
Intervention typeOther
Primary outcome measurePrevalence, incidence and progression rates of DR, measured using grading of OCT results annually for 5 years
Secondary outcome measuresThere are no secondary outcome measures
Overall study start date01/11/2017
Completion date31/10/2025

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit35 Years
Upper age limit85 Years
SexBoth
Target number of participants1185
Key inclusion criteria1. Aged 35–85 years
2. Diagnosed type 2 diabetes confirmed by medical records from endocrinologists, insulin treatments, oral medicine, fasting blood glucose ≥7.0 mmol/L for at least two consecutive measurements or postprandial blood glucose ≥11.1 mmol/L
3. Ocular-treatment-naïve eyes
Key exclusion criteria1. Any severe systemic disease, such as ischemic heart disease, stroke, cancer and kidney disease, or a history of systemic surgery, such as cardiac bypass, thrombolysis and kidney transplantation
2. Any cognitive disorder, mental disorder or failure to finish the questionnaire and all the examinations
3. Combined glaucoma, age-related macular degeneration, glaucoma, vitreous macular disease (vitreous haemorrhage, retinal detachment), amblyopia and other eye diseases
4. A history of intraocular surgery, such as retinal laser, intraocular anti-VEGF injection, glaucoma surgery, cataract surgery, laser myopia surgery and vitreoretinal surgery history
5. A failure of mydriasis due to corneal ulcer, severe refractive media turbidity or shallow anterior chamber and angle closure glaucoma
Date of first enrolment01/11/2017
Date of final enrolment31/10/2022

Locations

Countries of recruitment

  • China

Study participating centre

Zhongshan Ophthalmic Center
Sun Yat-sen University
No. 54 Xianlie Nan Road
Yuexiu District
Guangzhou
510000
China

Sponsor information

Sun Yat-sen University
University/education

Zhongshan Ophthalmic Center
No. 54. Xianlie Nan Road
Yuexiu District
Guangzhou
510000
China

Phone +86 (0)20 87334687
Email huangwenyong@gzzoc.com
Website http://www.gzzoc.com/
ROR logo "ROR" https://ror.org/0064kty71

Funders

Funder type

University/education

Sun Yat-sen University
Private sector organisation / Universities (academic only)
Alternative name(s)
SYSU
Location
China

Results and Publications

Intention to publish date31/10/2026
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination planThe results of the study will be presented as scientific article.
IPD sharing planThe datasets generated during and/or analysed during the current study will be available upon request from Prof. Wenyong Huang (hweny@mail.sysu.edu.cn). Informed consent will be obtained before the participant join the study. The study will follow the legal restrictions of the Ethics Committee of Zhongshan Ophthalmic Center, Sun Yat-sen University. For access to the data, please contact the principal investigator after the study completes.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article 26/05/2025 27/05/2025 Yes No
Results article 01/07/2025 02/07/2025 Yes No

Editorial Notes

02/07/2025: Publication reference added.
27/05/2025: Publication reference added.
12/01/2022: The following changes were made to the trial record:
1. The overall end date was changed from 31/10/2022 to 31/10/2025.
2. The intention to publish date was changed from 31/10/2023 to 31/10/2026.
3. The plain English summary was updated to reflect these changes.
02/04/2020: Trial's existence confirmed by Zhongshan Ophthalmic Center Ethics Committee.