VEGFA and non-proliferative diabetic retinopathy: Non-diabetic patients (ND), patients with non-proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy patients (PDR) had their venous blood plasma assessed for VEGF-Axxxb using an ELISA method adapted from [6] and VEGF-Axxx using Exon8apab.