Diabetic Retinopathy

Question 1

What is Diabetic retinopathy?

Answer 1

• This is a condition where the blood vessels in the retina are damaged by prolonged exposure to high blood sugar levels.
• This causes a progressive deterioration in the health of the retina

Question 2

What is the Pathophysiology of Diabetic Retinopathy?

Answer 2

• Hyperglycaemia leads to damage to the retinal small vessels and endothelial cells
• Increased vascular permeability leads to leakage from the blood vessels, blot haemorrhages and the formation of hard exudate ( yellow/white deposits of lipids in the retina)
• Microaneurysms (weakness in the wall causes small bulges) and venous beading (walks of the veins are no longer straight and parallel and look more like a string of beads or sausages) - due to the damage of the blood vessels walls
• Damage to the nerve fibres in the retina causes fluffy white patches to form on the retina = cotton wool spots
• Intraretinal microvascular abnormalities - where there are dilated and tortuous capillaries in the retina. These can act as a shunt between arterial and venous vessels in the retina
• Neovascularisation - growth factors are released in the retina causing the development of new blood vessels

Question 3

What is the classification of Diabetic Retinopathy?

Answer 3

• 2 categories: non-proliferative and proliferative
• non- proliferative ( background or pre-proliferative retinopathy) as can develop into proliferative retinopathy
• Diabetic maculopathy

Question 4

What is non-proliferative diabetic retinopathy?

Answer 4

• Mild: microaneurysms
• Moderate: microaneurysms, blot haemorrhages, hard exudates, cotton wool spots and venous beading
• Severe: blot haemorrhages plus microaneurysms in 4 quadrants, venous beading in 2 quadrants, intraretinal microvascular abnormality in any quadrant

Question 5

What is Proliferative Diabetic Retinopathy?

Answer 5

• Neovascularisation
• Vitreous Haemorrhage

Question 6

What is Diabetic Maculopathy?

Answer 6

• Macular oedema
• Ischaemic maculopathy

Question 7

What are the complications of Diabetic Retinopathy?

Answer 7

• Retinal detachment
• Vitreous Haemorrhage
• Rebeosis Iridis (new vessel formation in the iris)
• Optic neuropathy
• ## Cataracts

Question 8

What is the management of Diabetic Retinopathy?

Answer 8

Maculopathy:
- change in visual acuity = VEGF inhibitors
Non- Proliferative Retinopathy:
- Regular observation
- Severe/ very severe consider panretinal laser photocoagulation
Proliferative Retinopathy:
- Panretinal laser photocoagulation: around 50% develop a noticeable reduction in their visual field due to to the scarring of peripheral retinal tissue
- Intravitreal VEGF inhibitors: often now used in combination with panretinal laser photocoagulation, examples include ranibizumab. Slows progression of Proliferative diabetic retinopathy and improves visual acuity
- if severe or vitreous haemorrhage: vitreoretinal surgery