Prevalence and risk factors for diabetic retinopathy in a cross-sectional population-based study from rural southern China: Dongguan Eye Study

Research questionThe current population-based study aimed to investigate the prevalence of diabetic retinopathy (DR) and risk factors among residents over 40 years old in the rural area of Dongguan, southern China.Study designThe Dongguan Eye Study was a population-based study from September 2011 to February 2012.SettingThe area was set in the rural area of Dongguan, southern China.ParticipantsAdult rural population aged 40 or older.InterventionParticipants underwent haematological, physical, ophthalmic examinations and completed a questionnaire regarding lifestyles and systemic medical conditions.Primary and secondary outcome measuresThe frequency and risk factors of visual impairment and the major vision-threatening eye diseases.ResultsOf the 8952 Han Chinese, 1500 were diagnosed with type 2 diabetes mellitus (T2DM) with an average age of 59.5±11.1 years, and 1310 participants with fundus photography results were analysed. Standardised prevalence rate of DR was 18.2% for all patients with diabetes, 32.8% for the patients with previously diagnosed diabetes and 12.6% for newly diagnosed patients with T2DM. The prevalence rate of male DR was significantly higher than that of female DR (23.0% vs 14.1%, p