DM Flashcards
Pathophysiology of diabetic retinopathy?
1) Have hyperglycaemia
2) So get increased retinal blood flow and abnormal metabolism in the retinal vessel walls
3) This causes damage to endothelial cells and pericytes (cells involved in blood vessel formation
4) So leads to vascular occlusion and vascular leakage of retinal capillaries
5) So end up w/ retinal ischaemia, new vessel formation which are fragile and can haemorrhage causing sight loss + retinal scarring.
The details:
Endothelial damage —> leads to increased vascular permeability —> get exudates.
Pericyte damage —> causes microaneurysms to form.
Describe the classifications of diabetic retinopathy
Non-proliferative diabetic retinopathy (NPDR)
Proliferative retinopathy (PDR)
Maculopathy
What are key features of proliferative diabetic retinopathy?
- Retinal neovascularisation - may lead to virtuous haemorrhage
- Fibrous tissue forming anterior to retinal disc
- More common in T1DM
Key features of maculopathy?
- Based on location
- Hard exudates and changes on macula
-Macula oedema
-ischaemic maculopathy - Check visual acuity
- More common in T2DM
What conservative mangement would you suggest for diabetic retinopathy?
Optimise:
- blood sugar control
- blood pressure
- hyperlipidaemia
Management for maculopathy?
Conservative
+
intravitreal VEGF inhibitors if there are changes in visual acuity
Management for non-proliferative retinopathy?
Conservative
+
regular observation
If severe = panretinal laser photocoagulation
Management for proliferative retinopathy?
Conservative
+
panretinal laser photocoagulation
+
intravitreal VEGF inhibitors - e.g. bevacizumab
If severe or virtuous haemorrhage = vitreoretinal surgery
What is diabetic maculopathy?
Macular oedema caused by leakage of the vessels close to the macula. It can significantly threaten vision and should be treated with urgency
What fundoscopy signs are important to recognise for mild DM retinopathy?
Dots = micro aneurysms
What fundoscopy signs are important to recognise for severe NPDR retinopathy?
-Blot haemorrhages and microaneurysms in 4 quadrants
-Venous beading in at least 2 quadrants
-IRMA in at least 1 quadrant (intraretinal microvascular abnormalities)
In proliferative diabetic retinopathy, where are new blood vessels found in fudoscopy?
Retina or optic disc
Ddx for sudden visual loss in DM patient?
Vitreous haemorrhage is an important differential for sudden visual loss in diabetics
Cataracts is also a Ddx, as RF = DM.
Retinal Detachment
In diabetic retinopathy what do cotton wool spots indicate?
areas of retinal infarction
What are the features of MILD (NPDR) non prolif diabetic retinopathy?
1 or more microaneurysm
