Characteristics of population-based studies on the prevalence of diabetic retinopathy (DR) in mainland China.

Abbreviation: ETDRS, Early Treatment Diabetic Retinopathy Study; DR, diabetic retinopathy; NPDR, non-proliferative diabetic retinopathy; PDR, proliferative diabetic retinopathy. DM, diabetes mellitus; MDOC, mydriasis direct ophthalmoscope check; FFA, fundus fluorescein angiography; NMFP, non-mydriatic fundus photography; MFP, mydriatic fundus photography. NA, not available.*Staging of DR by Chinese academy of ocular fundus disease.**Proposed international clinical diabetic retinopathy and diabetic macular edema disease severity scales.