All of the following take part in the pathogenesis of macular edema in diabetic retinopathy except –
Etiopathogenis of diabetic retinopathy (including macular edema) 

Following factors are important in development of diabetic microangiopathy, which is responsible for the development of retinopathy :-


Activation of protein kinase C
Oxidative stress
Increased production of growth factors, amongst which Vascular endothelial growth factor A (VEGF-A is the most important). Other factors are TGF - β, PDGF, EGF and IGF
Retinal pigment epithelium dysfunction
Oxidative stress
VEGF
Increased protein kinase–C