Prevalence and Risk Factors for Diabetic Retinopathy: The Singapore Malay Eye Study

Received 14 January 2008; received in revised form 27 April 2008; accepted 6 May 2008. published online 26 June 2008.

Purpose

To describe the prevalence and risk factors of diabetic retinopathy in Asian Malays.

Design

Population-based cross-sectional study.

Participants

Persons with diabetes of Malay ethnicity aged 40 to 80 years in Singapore.

Methods

Diabetes mellitus was defined as random glucose of 11.1 mmol/l or more, use of diabetic medication, or a physician diagnosis of diabetes. Retinal photographs taken from both eyes were graded for diabetic retinopathy using the modified Airlie House classification system.

Main Outcome Measures

Any diabetic retinopathy, retinopathy grades, macular edema, or vision-threatening retinopathy.

Results

Of the 3261 persons who participated in this study, 757 (23.1%) had diabetes and gradable retinal photographs. In persons with diabetes, the overall prevalence of any retinopathy was 35.0% (95% confidence interval [CI], 28.2–43.4), the overall prevalence of macular edema was 5.7% (95% CI, 3.2–9.9), and the overall prevalence of vision-threatening retinopathy was 9.0% (95% CI, 5.8–13.8). Compared with men, women had significantly higher proportions with more severe diabetic retinopathy, moderate (12% vs. 4%) and severe (3% vs. 0.2%) nonproliferative retinopathy, proliferative retinopathy (7% vs. 2%), and vision-threatening retinopathy (13% vs. 3%). In multiple logistic regression, independent risk factors for any retinopathy were longer diabetes duration (odds ratio [OR], 1.07; 95% CI, 1.04–1.09, per year increase), higher hemoglobin A1c (OR, 1.21; 95% CI, 1.10–1.33, per % increase), hypertension (OR, 1.85; 95% CI, 1.04–3.30), and higher pulse pressure (OR, 1.34, 95% CI, 1.19–1.51, per 10-mmHg increase); older age (OR, 0.73; 95% CI, 0.57–0.93, per decade increase) and higher total cholesterol levels (OR, 0.75; 95% CI, 0.63–0.89, per 1-mmol/l increase) were protective of any retinopathy. Vision-threatening retinopathy additionally was associated with previous stroke (OR, 3.74; 95% CI, 1.24–11.26), cardiovascular disease (OR, 2.23; 95% CI, 1.08–4.62), and chronic kidney disease (OR, 4.45; 95% CI, 2.18–9.07). Female gender was not an independent risk factor for diabetic retinopathy after adjusting for metabolic and socioeconomic risk factors.

Conclusions

One in 10 Malay adults with diabetes in Singapore has vision-threatening diabetic retinopathy. Risk factors for retinopathy in this population are largely similar to white populations elsewhere, suggesting that control of these risk factors may reduce both the prevalence and impact of retinopathy.

Financial Disclosure(s)

The authors have no proprietary or commercial interest in any materials discussed in this article.

Available online: June 26, 2008.

1 Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia

2 Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore

3 Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore

4 Centre for Vision Research, University of Sydney, Sydney, Australia

5 Department of Community, Occupational and Family Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore

6 Department of Medicine, Alexandra Hospital, Singapore, Republic of Singapore

7 Department of Endocrinology, Singapore General Hospital, Singapore, Republic of Singapore

Correspondence: Tien Y. Wong, MD, PhD, Centre for Eye Research Australia, University of Melbourne, 32 Gisborne Street, Victoria 3002, Australia

Manuscript no. 2008-76.

Financial Disclosure(s): The authors have no conflicts of interests or financial disclosures related to this article.

Supported by the National Medical Research Council, Singapore (grant nos.: 0796/2003, 0863/2004, and CSI/0002/2005); and the Biomedical Research Council, Singapore (grant no.: 501/1/25–5). Additional support was provided by the Singapore Tissue Network and the Ministry of Health, Singapore.

PII: S0161-6420(08)00452-1

doi:10.1016/j.ophtha.2008.05.014

6 of 51