Eyes & Vision

Diabetic retinopathy

Diabetes damages retinal microvasculature, progressing from non-proliferative disease to ischaemia-driven neovascularisation, while diabetic macular oedema is a separate sight-threatening pathway; screening and stage-specific ophthalmic treatment prevent avoidable visual loss.

Definition

Diabetic retinopathy is diabetes-related microvascular disease of the retina. Non-proliferative retinopathy is characterised by retinal vascular leakage and non-perfusion; proliferative retinopathy is characterised by pathological neovascularisation. Diabetic macular oedema is a separate macular complication that may occur at any retinopathy stage.

First principles

Microvascular injury creates leakage and non-perfusion

Chronic hyperglycaemia damages retinal capillaries and their supporting cells. The early lesions are microaneurysms, intraretinal haemorrhages and hard exudates; progressive capillary closure produces ischaemia, cotton-wool spots, venous abnormalities and intraretinal microvascular abnormalities. Early disease is commonly asymptomatic, so visual acuity cannot be used as a proxy for retinal stage.

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