Table 2.
Sample analyzed | Study design | Sample size | Key findings | Method of analysis |
---|---|---|---|---|
VEGF (plasma) | Cavusoglu et al., 2007/Cross sectional | N = 83 (31 NPDR, 34 PDR,18 healthy controls) | VEGF levels increased significantly between NPDR and PDR (P = 0.016) and also between diabetics with NPDR vs. healthy controls (p < 0.000) as well as between PDR and healthy controls (p < 0.000) | ELISA (Biosource) sensitive to VEGF-165 |
VEGF (serum) | Du et al., 2014/Cross sectional (see also Table 4) | N = 69 diabetic patients (30 NDR, 23 NPDR, 16 PDR) | Increasing serum VEGF trend between no DR, NPDR and PDR groups; higher levels of VEGF in PDR vs. NPDR and NDR (p = 0.007 and p < 0.001, respectively); VEGF levels in NPDR vs. NDR also significantly higher (p = 0.007) | ELISA (human VEGF ELISA kit, Rapid Bio Lab, Calabasas, CA, USA) |
VEGF (serum) | Jain et al., 2013/cross sectional | N = 77 (19 NDR, 19 NPDR, 20 PDR, 19 healthy controls) | VEGF levels were significantly different between the study groups (p < 0.001) by ANOVA | Human VEGF ELISA kit, Invitrogen |
VEGF (serum) | Ozturk et al., 2009/cross sectional | N = 156 (31 NDR, 49 NPDR, 46 PDR, 28 healthy controls) | VEGF levels higher in those with NPDR compared to controls (p = 0.01), and in PDR compared to controls (p = 0.02). No significant difference between NPDR and PDR (p = 0.87) | Luminex multiplex bead immunoassay (Human Cytokine LINCOplex kit; LINCO Research, St Charles, MO) |
VEGF, Vascular Endothelial Growth Factor; NDR, diabetic with no retinopathy; NPDR, non-proliferative diabetic retinopathy; PDR, proliferative diabetic retinopathy.