After adjusting for age, smoking status, duration of DM and systemic illness (hypertension and dyslipidaemia), the PDR group showed highest mean level of VEGF in serum among type 2 DM patients (342.4 SD 41.5 pg/mL) compared to NPDR (288.7 SD 34.8 pg/mL) and no DR (305.4 SD 43.0 pg/mL). This evidence concerns the gene VEGFA and diabetes mellitus.