In order to assess the potential biochemical markers in the development, diagnosis, and prognosis of diabetic patient with microvascular complication represented with retinopathy, we analyzed the levels of cell-free DNA by two different techniques. The levels of cell-free GAPDH assayed by quantitative PCR were significantly higher in the plasma samples of diabetic patients with and without diabetic retinopathy than in those of the control group; thus, it is a better biomarker than nucleosomes assayed by ELISA in patients with type 2 diabetes for the early detection of development of microvascular complications as retinopathy.