3.2.1. Retinal pathophysiology: key features that need to be represented in animal models
Diabetic retinopathy is the leading cause of visual impairment leading to blindness impacting approximately one third of the diabetic population[121]. Hyperglycaemia induced vascular damage involves several metabolic pathways analogous to those affecting diabetic nephropathy, including the polyol pathway, formation of AGEs and the PKC pathway. These pathways accelerate the loss of pericytes, apoptosis of endothelial cells, microaneurysms and thickening of the basement membrane, resulting in capillary occlusions and ischaemia. These processes trigger the upregulation of the growth factor VEGF, promoting vascular permeability and angiogenesis. This contributes to the progression of proliferative diabetic retinopathy and diabetic macular oedema, ultimately leading to vision loss and blindness[122].