prevalence and risk factors of diabetic retinopathy in yazd province

purpose: to describe the prevalence and risk factors of diabetic retinopathy (dr) in adults aged 40-80 years in yazd province in 2011. methods: this is a population-based survey on 2,320 urban and rural residents of yazd province. random multi-stage cluster sampling was employed in the survey. diagnosis of diabetes was made upon past medical history and drug history or insulin injection and in cases without history of diabetes upon two fasting blood sugar exceeding 126 mg/dl. a detailed interview, eye examination and stereoscopic fundus photography were conducted for each eligible participant. dr definition and grading were based on etdrs definition and the international clinical diabetic retinopathy disease severity scale. results: out of the eligible individuals, 2,098 cases (90.1%) participated in the study. the standardized prevalence of diabetes was 24.5% (95% confidence interval, 22.5-26.8%), 29.6% (25-34.3) of diabetics were diagnosed with dr. the prevalence of mild, moderate and severe forms of nonproliferative diabetic retinopathy (npdr) and proliferative diabetic retinopathy (pdr) was 12.7% (95%ci, 9.5-15.8%), 11.8% (95%ci, 9-14.7%), 9.9% (95%ci, 6.6-13.3%), and 3.9% (2-5.8%), respectively. the prevalence of clinically significant macular edema (csme) was 4.9% (2.7-7.2%) and vision-threatening diabetic retinopathy including severe ndpr, pdr and csme was present in 11.1% (7.9-14.3%) of cases. conclusion: this study showed that out of every four people above 40, one had diabetes and out of every three diabetic patients one had dr. the high prevalence rates of diabetes and dr indicate the need for adequate prevention and management strategies in the study population.