Diabetic retinopathy: neuron protection as a therapeutic target.

Diabetic retinopathy (DR) has mainly been regarded as a microvascular disease that is caused by hyperglycaemia and characterized by retinal vascular leakage, macular oedema and preretinal neovascularisation. Increasing clinical evidence from electroretinographic, contrast sensitivity, perimetric, and colour vision studies suggest that neuronal changes may occur prior to clinically detectable microvasculopathy. Thus, there may be a primary neurodegenerative process which contributes to loss of vision in DR. Neuronal apoptosis in DR has been reported both in vivo and in vitro. Consequently, neuroprotection in DR may be a valuable therapeutic target. This review outlines the recent new concepts of neurodegeneration in the pathogenesis of DR, particularly emphasising its potential for new therapeutic approaches.