OBJECTIVETo examine the global prevalence and major risk factors for diabetic retinopathy (DR) and vision-threatening diabetic retinopathy (VTDR) among people with diabetes.RESEARCH DESIGN AND METHODSA pooled analysis using individual participant data from population-based studies around the world was performed. A systematic literature review was conducted to identify all population-based studies in general populations or individuals with diabetes who had ascertained DR from retinal photographs. Studies provided data for DR end points, including any DR, proliferative DR, diabetic macular edema, and VTDR, and also major systemic risk factors. Pooled prevalence estimates were directly age-standardized to the 2010 World Diabetes Population aged 20–79 years.RESULTSA total of 35 studies (1980–2008) provided data from 22,896 individuals with diabetes. The overall prevalence was 34.6% (95% CI 34.5–34.8) for any DR, 6.96% (6.87–7.04) for proliferative DR, 6.81% (6.74–6.89) for diabetic macular edema, and 10.2% (10.1–10.3) for VTDR. All DR prevalence end points increased with diabetes duration, hemoglobin A1c, and blood pressure levels and were higher in people with type 1 compared with type 2 diabetes.CONCLUSIONSThere are approximately 93 million people with DR, 17 million with proliferative DR, 21 million with diabetic macular edema, and 28 million with VTDR worldwide. Longer diabetes duration and poorer glycemic and blood pressure control are strongly associated with DR. These data highlight the substantial worldwide public health burden of DR and the importance of modifiable risk factors in its occurrence. This study is limited by data pooled from studies at different time points, with different methodologies and population characteristics.

Objective-To summarize the prevalence of retinal vein occlusion (RVO) from studies in the United States, Europe, Asia, and Australia. Design-Pooled analysis using individual population-based data.Participants-Individual participant data from population-based studies around the world that had ascertained RVO from fundus photographs.Methods-Each study provided data on branch RVO and central RVO by age, sex, and ethnicity. Prevalence rates were directly age and sex standardized to the 2008 world population aged 30 years and older. Estimates were calculated by study and, after pooling, by ethnicity. Summary estimates included studies in which RVO was assessed from fundus photographs on ≥2 fields of both eyes. Main Outcome Measures-Any RVO, CRVO, or BRVO.Results-The combined pooled data contained 68,751 individuals from 15 studies, with participants' ages ranging from 30 to 101 years. In analyses of 11 studies that assessed ≥2 fundus fields of both eyes (n=49,869), the age-and sex-standardized prevalence was 5.20 per 1000 (confidence interval [CI], 4.40-5.99) for any RVO, 4.42 per 1000 (CI, 3.65-5.19) for BRVO, and 0.80 per 1000 (CI, 0.61-0.99) for CRVO. Prevalence varied by race/ethnicity and increased with age, but did not differ by gender. The age-and sex-standardized prevalence of any RVO was 3.7 per 1000 (CI, 2.8-4.6) in whites (5 studies), 3.9 per 1000 (CI, 1.8-6.0) in blacks (1 study), 5.7 per 1000 (CI, 4.5-6.8) in Asians (6 studies), and 6.9 per 1000 (CI,3) in Hispanics (3 studies). Prevalence for CRVO was lower than BRVO in all ethnic populations. On the basis of these data, an estimated (CI, adults are affected by RVO, with 2.5 million (CI, 1.9-3.1) affected by CRVO and 13.9 million (CI, 11.5-16.4) affected by BRVO. Study limitations include non-uniform sampling frames in identifying study participants and in acquisition and grading of RVO data.Conclusions-Our study provides summary data on the prevalence of RVO and suggests that approximately 16 million people may have this condition. Research on preventive and treatment strategies for this sight-threatening eye disease is needed.Retinal vein occlusion (RVO) is one of the most common causes of acquired retinal vascular abnormality in adults and a frequent cause of visual loss. Despite being recognized at least as early as 1855 1 and the subject of more than 3000 publications, there are few data on the prevalence of RVO in the general population, with current estimates derived largely from studies in white populations. [2][3][4] More recently, population data have emerged from other racial/ ethnic groups, such as in Chinese, 5 Hispanics, 6 and Asian Malays. 7 The reported prevalence of RVO varies between 0.3% 4 and 1.6%. 3 The variability in prevalence rates is likely related to the small number of RVO cases in any single study, differing study methodologies (e.g., retinal photography), and possible racial/ethnic differences in distributions of RVO risk factors.Because of these limitations, estimates of RVO prevalence have been imprecise. Furthermo...

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Visual acuity generally improved in eyes with BRVO without intervention, although clinically significant improvement beyond 20/40 was uncommon.