A 54-year-old man with type 2 diabetes mellitus is found on annual review to have new vessel formation at the optic disc. Visual acuity in both eyes is not affected (6/9). Blood pressure is155/84 mmHg, HbA1c 8.4%.
What is the most important intervention in this patient?
Correct Answer E: This patient has proliferative diabetic retinopathy and urgent referral to an ophthalmologist for panretinal photocoagulation is indicated.
Diabetic retinopathy:
Diabetic retinopathy is the most common cause of blindness in adults aged 35-65 years-old. Hyperglycaemia is thought to cause increased retinal blood flow and abnormal metabolism in the retinal vessel walls. This precipitates damage to endothelial cells and pericytes.
Endothelial dysfunction leads to increased vascular permeability which causes the characteristic exudates seen on fundoscopy. Pericyte dysfunction predisposes to the formation of microaneurysms. Neo-vasculization is thought to be caused by the production of growth factors in response to retinal ischaemia.
In exams you are most likely to be asked about the characteristic features of the various stages/types of diabetic retinopathy. Recently a new classification system has been proposed, dividing patients into those with nonproliferative diabetic retinopathy (NPDR) and those with proliferative retinopathy (PDR):
A 64-year-old patient is prescribed pegvisomant for the treatment of acromegaly.
What is the mechanism of action of pegvisomant?
Correct Answer B:
Acromegaly: management:
Trans-sphenoidal surgery is first-line treatment for acromegaly in the majority of patients.
Dopamine agonists:
Somatostatin analogue:
Pegvisomant:
Which one of the following is most likely to be seen in a patient with multiple endocrine neoplasia (MEN) type I?
Multiple endocrine neoplasia: The table below summarizes the three main types of multiple endocrine neoplasia (MEN):
MEN is inherited as an autosomal dominant disorder.
Which one of the following may be associated with galactorrhoea?
Correct Answer A:
Prolactin and galactorrhoea:
Prolactin is secreted by the anterior pituitary gland with release being controlled by a wide variety of physiological factors. Dopamine acts as the primary prolactin releasing inhibitory factor and hence dopamine agonists such as bromocriptine may be used to control galactorrhoea. It is important to differentiate the causes of galactorrhoea (due to the actions of prolactin on breast tissue) from those of gynaecomastia.
Features of excess prolactin:
Causes of raised prolactin:
Drug causes of raised prolactin:
Which one of the following statements regarding polycystic ovarian syndrome (PCOS) is INCORRECT?
Correct Answer E: Polycystic ovarian syndrome is extremely common, affecting between 5-20% of women of reproductive age.
Polycystic ovarian syndrome: features and investigation:
Polycystic ovary syndrome (PCOS) is a complex condition of ovarian dysfunction thought to affect between 5- 20% of women of reproductive age. The aetiology of PCOS is not fully understood. Both hyperinsulinaemia and high levels of luteinizing hormone are seen in PCOS and there appears to be some overlap with the metabolic syndrome.
Features:
Investigations:
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