Prevalence of diabetic retinopathy in adult Chinese American individuals: The Chinese American eye study

IMPORTANCE Chinese American individuals are a fast-growing segment of people in the United States, but the burden and effect of diabetic complications on this group of people is not fully understood. OBJECTIVE To determine the age- and sex-specific prevalence of diabetic retinopathy (DR) overall and by severity, duration of diabetes, and treatment history in adult Chinese American individuals. DESIGN, SETTING, AND PARTICIPANTS The Chinese American Eye Study (CHES), a population-based, cross-sectional study, was conducted from February 2010 to October 2013 for 10 census tracts in Monterey Park, California. This analysis, conducted between February 16, 2010, and October 9, 2013, included 4582 Chinese residents 50 years and older. MAIN OUTCOMES AND MEASURES Prevalence of nonproliferative DR, proliferative DR, and macular edema, as well as stereoscopic fundus photography of 7 standard Early Treatment Diabetic Retinopathy Study fields. RESULTS Of the 4582 survey participants, most were first-generation immigrants from China (68.7%) and female (63%). In total, 736 participants (16.1%) were identified as having type 2 diabetes. Fundus photographs were gradable for 665 (90.4%) of these participants. The reproducibility of DR grading was evaluated throughout study and showed moderate to excellent agreement (weighted ê = 0.78-0.97). Diabetic retinopathy was present in 35.8% of people with diabetes (95%CI, 32.1%-39.6%). The estimated prevalence of severe nonproliferative DR and proliferative DR was 1.7%(95%CI, 0.8%-2.9%) and 2.4%(95%CI, 1.4%-3.9%), respectively. Macular edema was observed among 4.5%of people with diabetes (95%CI, 3.0%-6.4%), and clinically significant macular edema was observed among 2.0% (95%CI, 1.1%-3.3%). The prevalence of DR was higher (56%) among participants with a longer duration of diabetes (15 years; P < .001). The prevalence of visual impairment (best-corrected visual acuity worse than 20/40 in the better-seeing eye) among participants with diabetes was higher than those without diabetes (6.7%vs 2.2% = difference of 4.5%; 95%CI, 3.9%-5.1%). The primary causes of visual impairment in participants with diabetes were cataracts (38%of participants; 95%CI, 36.6%-39.4%) followed by macular edema (7% of participants; 95%CI, 6.3%-7.7%). CONCLUSIONS AND RELEVANCE Data from CHES and this study indicate that the prevalence of DR in the Chinese American Eye Study Group is relatively lower than studies of Chinese individuals residing in rural northern China or Latino individuals from Los Angeles County, California.