Diabetic and Hypertensive Retinopathy

These conditions are very common and thus their effects on the eye are important. The stages of damage should be remembered, and you should be able to recognise and distinguish the conditions on ophthalmic pictures.

Diabetes

Background

Micro-aneurysms (small red circular outpouchings of the capillaries), dot and blot haemorrhages (red blots), flame shaped haemorrhages, hard exudates (yellow/white sharply defined spots which represent lipids leaking through the vessels). Vision is usually normal.

Pre-proliferative

Cotton wool spots (larger white spots with fluffy edges which represent infarcts of the retina), large blot haemorrhages. 50% progress to proliferative retinopathy in 1-2 years.

Proliferative

Neovascularization (new vessel formation, usually occurring at the optic disc), vitreous haemorrhage (due to bleeding from the fragile new vessels). This predisposes individuals to retinal detachment, due to fibrovascular bands forming around the new vessels and tugging on the retina. Neovascularization can be prevented by laser ablation of ischaemic areas (ischaemia is the stimulus for the vessel formation).

Maculopathy

Causing loss of vision.

Diabetics are additionally more prone to complications including glaucoma and cataracts.

Hypertension

Stage 1

Increased tortuosity and reflectiveness (known as silver wiring).

Stage 2

Arteriovenous nipping.

Stage 3

Flame shaped haemorrhages, cotton wool spots.

Stage 4

Papilloedema.

Hypertensive complications include retinal vein and artery occlusion, ischaemic optic neuropathy and vitreous haemorrhage.

Retinal detachment

The patient experiences preceding photopsia (flashes of light) and "floaters" (visual opacities from haemorrhage). Next a "shadow" spreads across the field of vision. Central vision is lost as the macular area is affected. Blindness may develop in severe cases.

Associated with: diabetes mellitus, macular degeneration, retinoblastoma, uveitis, and trauma.