Diabetic Retinopathy Flashcards
What are the RF of developing diabetic retinopathy?
Long duration of DM
Poor glycaemic control
Hypertension
Renal Disease
Anaemia
Obesity
Hyperlipidaemia
Smoking
Pregnancy
Describe the pathogenesis of diabetic retinopathy?
Hyperglycaemia causes:
BM thickening
Endothelial cell damage
RBC changes
Increase platelet stickiness
Aka good environment for thrombo-emboli formation.
Describe the pathogenesis behind microaneurysms forming?
An occlusion due to a thromboembolus occurs and there is death of Pericytes (contractile cells that wrap around the endothelial cells of capillaries and venules throughout the body).
This results in there being a weakness and therefore microaneurysms form and which may bleed.
Describe why hard exudates form?
Hard exudates form when there is leakage from microaneurysms which are then phagocytosed by macrophages.
Describe the proliferation which occurs in diabetic retinopathy?
Due to the blockage the retina tries to form collaterals by producing a-v shunts to try and increase perfusion these are called ‘Intraretinal Microvascular Abnormalaties’.
As well as this there is angiogenesis of new vessels, however these are more prone to haemorrhage.
What are the different classifications of diabetic retinopathy?
- Background
- Pre-proliferative
- Proliferative (60% risk after 30yrs of DM)
- Maculopathy
What are the signs of background retinopathy?
Dots, blots, superficial flame shape haemorrhages.
Microaneurysms.
Hard exudates.
What are the signs of pre-proliferative retinopathy?
- Cotton wool spots,
- Venous irregularities (bending of veins),
- Dark blot hameorrhages,
- Intraretinalmicrovascular abnormalaties (IRMA)
What are the signs of proliferative retinopathy?
Neovascularisation of disc (NVD)
Neovascularistaion elsewhere (NVE) (iris, retina)
Rubeosis Iridis. (new blood vessels around the iris)
Haemorrhage, vitreous/ pre retinal.
What sign can you see in the image? What is this a sign of?
Rubeosis Iridisis
Proliferative retinopathy
