Plasma melatonin levels in patients with diabetic retinopathy secondary to type 2 diabetes

Figure 1 Flowchart demonstrates the number of patients enrolled, grouping, examination and analyses in the study. NDR: Without diabetic retinopathy; NPDR: Non-proliferative diabetic retinopathy; PDR: Proliferative diabetic retinopathy.

Figure 2 Plasma melatonin concentrations in healthy controls and diabetic retinopathy patients. A: Plasma melatonin in the healthy controls, without diabetic retinopathy (NDR), non-proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR) groups; B: The diagnostic effect of plasma melatonin on diabetic retinopathy was discovered using the receiver operating characteristic curve. ^aP < 0.001. NDR: Without diabetic retinopathy; NPDR: Non-proliferative diabetic retinopathy; PDR: Proliferative diabetic retinopathy; DM: Diabetes mellitus; AUC: Area under the receiver operating characteristic curve.

Figure 3 Linear relationship between total bilirubin and melatonin concentration in the different groups. A: The linear relationship in all the participants; B: The linear relationship in the non-proliferative diabetic retinopathy (NPDR) group; C: The linear relationship in the proliferative diabetic retinopathy (PDR) group. NPDR: Non-proliferative diabetic retinopathy; PDR: Proliferative diabetic retinopathy.