Fig. 2

a ROC curve for distinction between cases and controls, AUC = 0.858 (p < 0.001). b ROC curve for distinction of diabetic retinopathy and no retinopathy in cases, AUC = 0.791 (p < 0.001). c ROC curve for distinction between non-proliferative and proliferative diabetic retinopathy, AUC = 0.761 (p < 0.001)