Hypertensive retinopathy describes the damage to the small blood vessels in the retina relating to systemic hypertension. This can be the result of years of chronic hypertension or can develop quickly in response to malignant hypertension. There are a number of signs that occur within the retina in response to the effects of hypertension in these vessels.
Silver wiring or copper wiring is where the walls of the arterioles become thickened and sclerosed causing increased reflection of the light.
Arteriovenous nipping is where the arterioles cause compression of the veins where they cross. This is again due to sclerosis and hardening of the arterioles.
Cotton wool spots are caused by ischaemia and infarction in the retina causing damage to nerve fibres.
Hard exudates are caused by damaged vessels leaking lipids into the retina.
Retinal haemorrhages are caused by damaged vessels rupturing and releasing blood into the retina.
Papilloedema is caused by ischaemia to the optic nerve resulting in optic nerve swelling (oedema) and blurring of the disc margins.
- Stage 1: Mild narrowing of the arterioles
- Stage 2: Focal constriction of blood vessels and AV nicking
- Stage 3: Cotton-wool patches, exudates and haemorrhages
- Stage 4: Papilloedema
Management is focused on controlling the blood pressure and other risk factors such as smoking and blood lipid levels.