Overview Diabetes is the most common cause of blindness in the working population. Blindness is preventable. Annual retinal screening is advised for patients at risk. Pre-symptomatic screening enables laser photocoagulation to be used, aimed to stop production of angiogenic factors from the ischaemic retina.
Clinical features The fundus are usually bilateral and broadly symmetrical.
Findings depend on severity and are classified into:
Non-proliferative diabetic retinopathy
Proliferative diabetic retinopathy
|Risk Factors for worsening retinopathy
|Duration of diabetes
|Type 1 diabetes
|Poor diabetic control
Overview Type II diabetes Mellitus is the leading cause of Chronic Kidney Disease. It is classified as a secondary nephrotic syndrome. ~10% of will people will have nephropathy at diagnosis and up to half will go on to develop it over the next 20yrs. 20% of people with Type II diabetes will develop end stage kidney disease. Everyone with Diabetes should be screened yearly for microalbuminuria.
Clinical features - Nephrotic Syndrome with signs and symptoms of diabetes (hyperglycemia)
More info on Nephrotic Syndrome
Pathological features Diabetic kidney disease is defined by characteristic structural and functional changes. The predominant structural changes include
|Isolated glomerular basement membrane thickening. There is no evidence of mesangial expansion, increased mesangial matrix, or global glomerulosclerosis involving >50 percent of glomeruli.
|Mild (class IIa) or severe (class IIb) mesangial expansion.
|At least one Kimmelstiel-Wilson lesion (nodular intercapillary glomerulosclerosis) is observed on biopsy and there is <50 percent global glomerulosclerosis.
|Advanced diabetic sclerosis. There is >50 percent global glomerulosclerosis.
Management and Prognosis - Microalbuminuria is reversible if caught early and managed vigorously:
More info on Chronic Kidney Disease
Overview Involvement of the peripheral and autonomic nervous systems is probably the most common complication of diabetes. The high rate of diabetic neuropathy results in substantial morbidity, including recurrent lower extremity infections, ulcerations, and subsequent amputations
|Side note Gastroparesis is characterised by early satiety, post-prandial bloating and nausea/vomiting. It is diagnosed by gastric scintigraphy with a technutium labelled meal.
Overview The high rate of diabetic neuropathy results in substantial morbidity, including recurrent lower extremity infections, ulcerations, and subsequent amputations. The combination of peripheral vascular disease and peripheral neuropathy can lead to repeated minor trauma to the feet leading to ulceration and infection which are very slow to heal. Examine foot regularly.
Clinical features Typically painless, punched out ulcer in an area of thick callus +/- superadded infection. This can then lead to cellulitis, abscess +/- osteomyelitis.
|Remember To examine foot regularly. Distinguish between ischaemia (absent foot pulses) and peripheral neuropathy (↓sensation in stocking distribution, absent ankle reflex, charcot's joints). Many have both ischaemic and neuropathic changes
Assess degree of:
In cases of infections the common organisms are staphs, streps, anaerobes. Treat with IV benzylpenicillin and flucloxacillin +/- metronidazole
More info on lower limb ulcers
|Pharmacology Metronidazole inhibits nucleic acid synthesis in microbes, more effective against anaerobic microorganisms. Side effects: nausea, diarrhoea, weight loss, abdominal pain, vomiting, headache, dizziness, metallic taste in the mouth. Rarer side effects: thrombophlebitis, leukopenia, neutropenia and peripheral neuropathy