Complications Flashcards
What are the causes of visual impairment in someone with diabetes?
- Maculopathy
- Glaucoma
- Cataracts
- Diabetic retinopathy
How would you manage somoene with signs of retinopathy?
- Yearly screening
- Good glycaemic control - HbA1c < 58 mmol/L
- Blood pressure control - <130/80) - ACEi/amlodipine
- Refer to opthalmology
What are pathophysiological consequences of diabetes?
Non-enzymatic glycosylation of a wide variety of proteins e.g. haemoglobin, collagen, LDL and tubulin in peripheral nerves -> leads to an accumulation of advanced glycosylated end-products causing injury and inflammation
Changes in vascular permeability, cell proliferation and capillary structure - due to metabolism of glucose
Abnormal microvascular blood flow
Haemodynamic changes - kidney
What macrovascular complications occur in diabetes?
Accelerated atheroma
- Stroke
- MI
- Peripheral vascular disease
What microvascular complications occur in diabetes?
- Eye disease
- Renal disease
- Neuropathy
What are the main complications seen in diabetes?
- Microvascular - Eye disease, renal disease, neuropathy - peripheral, auonomic
- Macrovascular - Stroke, MI
- Diabetic foot
- Infections
- Gastroparesis
How would you attempt to manage the risk of macrovascular complications?
- Target HbA1c 53 mmols/mol (7%)
- Control BP to < 130/80
- Smoking cessation
- Statin therapy
- Lifestyle choices
What are the main diabetic eye diseases?
- Cataracts
- Diabetic retinopathy
- Glaucoma
- External ocular nerve palsies
What is the main cause of diabetic eye disease?
Diabetic retinopathy
Why does cataracts occur in diabetes?
This can be due to reversible osmotic changes in patients with acute hyperglycaemia. It may also be due to senile cataracts.
What is the following?
Cataracts
How would you manage someone who had developed cataracts as a complication of diabetes?
- Senile - consider surgery
- Juvenile “snowflake” - better glycaemic control
What is juvenile “snowflake” cataracts?
Sustained very poor diabetes control with a degree of ketosis can cause an acute cataract (snowflake cataract), which comes on rapidly. Fluctuations in blood glucose concentration can cause refractive variability, as a result of osmotic changes within the lens (the absorption of water into the lens causes temporary hypermetropica). This presents as fluctuating difficulty in reading. It resolves with better metabolic control of the diabetes.
Why can glaucoma occur in diabetes?
New vessel formation can occur in the iris in late stage diabetes, which can lead to galucoma by blocking the natural drainage pathways of the eye.
What could be the following in the context of a diabetic patient?
Glaucoma
What is the pathophysiology of diabetic retinopathy?
The metabolic consequences of poorly-controlled diabetes cause intramural pericyte death, and thickening of the basement membrane in the small blood vessels of the retina. This leads initially to incompetence and increased permeability of the vascular walls, and later to occlusion of the vessels (capillary closure). This process has somewhat different consequences in the peripheral retina and in the macular area.
What are the effecs of diabetes on the peripheral retina?
- Microaneurysms
- Superficial (blot) haemorrhages
- Hard exudates - protein and lipid deposits left after fluid is cleared into retinal veins
- Cotton wool spots - Micro-infarcts within the retina due to occluded vessels. Spots themselves are caused by axoplasmic debris
- Neovascularization
- Retinal haemorrhage
What are the following?
- Microaneurysm - small circles
- Blot Haemorrhage - Large Circles
What are dot/blot haemorrhages?
Larger red dots with distinct (dot) or indistinct (blot) borders. Caused by burst blood vessel in the retina
What stage of retinopathy can be seen in this individuals eye (who has diabetes)?
Background retinopathy - Dot/bloot haemorrhages, microaneurysms
What are the stages of diabetic retinopathy?
- Background retinopathy
- Pre-proliferative retinopathy
- Proliferative retinopathy
- Advanced retinopathy
Maculopathy can also occur at any of these stages
What stage of retinopathy can be seen in this individuals eye (who has diabetes)?
Background retinopathy - Hard exudates
What are cotton wool spots?
Ischaemic swelling of the optic nerve layer causes a white, round or patchy appearance (circled)
What are features of background retinopathy in diabetes?
-
Haemorrhage
- Dot/blot/flame
-
Oedema
- Leakage of fluid (transudate)
- Macular oedema can occur in background
-
Microaneurysms
- out pouchings of venous end capillaries
- Earliest sign of retinopathy found in central macula
-
Exudates
- Hard exudates
- Leakage of plasma rich lipids and proteins
- Yellowish deposits
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What are features of pre-proliferative retinopathy?
-
Cotton wool spots
- Oedema from retinal infarcts
- Haemorrhages
- Venous bleeding
- Retinal ischaemia signs
- Intra-retinal microvascular abnormalities
What stage of diabetic eye disease is the following?
Pre-proliferative disease - A Small dot haemorrhages, microaneurysms, hard (lipid) exudates, circinate retinopathy, an intraretinal microvascular abnormality and macular oedema
What are the following?
Intra-retinal microvascular abnormalities (IRMAs)
What are features of proliferative retinopathy in someone with diabetes?
New vessel formation arising from optic disk or vessels
- On retina
- On optic disc
- On iris
- Can cause vitreous haemorrhage
What is the following, and what is it indicative of?
DIFFICULT TO SEE!!!
Venous loop - a type of Intra-retinal microvasulcar abnormality indicitave of pre-proliferative disease
What stage of diabetic eye disease is the following?
Proliferative - fronds of new vessels formed
What stage of diabetic eye disease is the following?
Severe proliferative disease - with cotton wool spots, intraretinal microvascular abnormalities and venous bleeding
What is maculopathy?
Thickening and oedema involving the macula