[9] Diabetic Retinopathy Flashcards
What eye problems can be associated with diabetes mellitus (DM)?
- Diabetic retinopathy (most common)
- Cataracts
- Rubeosis iridis and glaucoma
- Oculomotor nerve palsies
What is diabetic retinopathy?
A chronic progressive, potentially sight-threatening disease of the retinal microvasculature
What is diabetic retinopathy associated with?
Prolonged hyperglycaemia of DM and other diabetes-linked conditions such as hypertension
How is diabetic retinopathy classified?
Based on the ares of the retina affected and the degree of pathology seen on slit lamp examination
What are the two broad types of diabetic retinopathy?
- Diabetic retinopathy
- Diabetic maculopathy (I think this is potentially a separate thing thats closely related but idk so lets roll with it)
What are the classifications of diabetic retinopathy (DR)?
- Background (mild) non-proliferative DR
- Moderate non-proliferative DR
- Severe to very severe non-proliferative DR
- Non-high risk proliferative DR
- High-risk proliferative DR
What is background non-proliferative diabetic retinopathy?
1 microaneurysm seen on slit lamp examination on background of DM
What is moderate non-proliferative diabetic retinopathy?
Moderate amount of micro-aneurysms and intra-retinal haemorrhages with or without cotton wool spots, venous beading or other intra-retinal micro-vascular abnormalities
What is severe to very severe non-proliferative diabetic retinopathy?
Like moderate but more severe (obvs)
What is non-high risk proliferative diabetic retinopathy?
Where there are new vessels on the disc (or within 1 disc diameter) or elsewhere
What is high risk proliferative diabetic retinopathy?
- Large new vessels on the disc or elsewhere
- Potentially pre-retinal haemorrhages
- Potentially retinal detachment in advanced disease
What are the types of diabetic maculopathy?
- Focal or diffuse macular oedema
- Ischaemic maculopathy
- Clinically significant macular oedema
What are the features of focal or diffuse macular oedema diabetic maculopathy?
What are the features of focal or diffuse macular oedema diabetic maculopathy?
What are the features of ischaemic diabetic maculopathy?
- Clinically appear relatively normal
- Visual acuity is dropped
- Ischaemia seen on fluorescein angiography
What are the features of clinically significant macular oedema?
- Thickening of the retina
- Hard exudates around the fovea or above a certain size
What causes diabetic retinopathy?
Diabetes mellitus
What is the mechanism behind diabetic retinopathy?
Microvascular occlusions cause retinal ischaemia leading to arteriovenous shunting, neovascularisation, intra retinal haemorrhages and oedema
What are the characteristic features that can be seen at different stages of diabetic retinopathy?
- Micro-aneurysms
- Hard exudates
- Haemorrhages
- Cotton wool spots
- Neovascularisation
What are micro-aneurysms in diabetic retinopathy?
Physical weakening of the capillary walls that predispose them to leakages
What are hard exudates in diabetic retinopathy?
Precipitates of lipoproteins/other proteins leaking from the retinal blood vessels
What are the haemorrhages seen in diabetic retinopathy?
Rupturing of weakened capillaries, appearing as small dots/larger blots or ‘flame’ haemorrhages that track along nerve-fibre bundles in superficial retinal layers
What are cotton wool spots seen in diabetic retinopathy?
Build up of axonal debris due to poor axonal metabolism in the margins of ischaemic infarcts
What is neovascularisation in diabetic retinopathy?
An attempt by residual healthy retina to revascularise hypoxic retinal tissue
What is progression of diabetic retinopathy mainly associated with?
Severity and length of hyperglycaemia
What are some other risk factors that influence onset and progression of diabetic retinopathy?
- Hypertension
- Other cardiovascular risk factors
- Pregnancy
- Minority ethnic community
- Intraocular surgery
What are some excellent predictors of the presence of diabetic retinopathy?
- Renal disease evidenced by proteinuria and elevated serum urea/creatinine
When should eye screening be performed in patients with diabetes?
At or around the time of diagnosis and then repeated annually
How is diabetic retinopathy screening conducted?
Via photographing the dilated retina