Diabetic and Hypertensive retinopathy
Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management
Definition
Diabetic retinopathy and hypertensive retinopathy are vascular complications of diabetes and hypertension, respectively, affecting the retina and leading to progressive visual impairment.
Aetiology
- Diabetic retinopathy: chronic hyperglycaemia causes microvascular damage, leading to capillary leakage and ischaemia.
- Hypertensive retinopathy: prolonged hypertension leads to endothelial dysfunction, vessel narrowing, and haemorrhages.
Pathophysiology
- Diabetic retinopathy progresses from non-proliferative (microaneurysms, haemorrhages) to proliferative (neovascularisation, vitreous haemorrhage).
- Hypertensive retinopathy leads to arteriosclerosis, increased vascular permeability, and potential optic nerve swelling in severe cases.
Risk Factors
- Poorly controlled diabetes mellitus (diabetic retinopathy).
- Long-standing hypertension (hypertensive retinopathy).
- Smoking and hyperlipidaemia.
- Chronic kidney disease.
Signs and Symptoms
- Diabetic retinopathy:
- Blurred vision.
- Floaters from vitreous haemorrhage.
- Macular oedema affecting central vision.
- Hypertensive retinopathy:
- Arteriolar narrowing (silver wiring appearance).
- Flame shaped haemorrhages.
- Papilloedema in malignant hypertension.
Investigations
- Fundoscopy: assesses retinal changes.
- Fluorescein angiography: evaluates retinal vascular leakage.
- OCT (optical coherence tomography): detects macular oedema.
- Blood pressure measurement: screens for hypertension.
- HbA1c: assesses long term glycaemic control.
Management
1. Diabetic Retinopathy:
- Glycaemic control: optimising HbA1c reduces progression risk. The aim is an HBa1c between 48 - 53 mmol/mol.
- Anti-VEGF therapy: an injection e.g. ranibizuma for macular oedema
- Laser photocoagulation: prevents neovascular complications.
2. Hypertensive Retinopathy:
- Blood pressure control: ain for BP <130/80 (if possible).
- Management of cardiovascular risk factors: smoking cessation, lipid control (statin if Qrisk >10%).
3. Referral:
- Ophthalmology: all patients with diabetic retinopathy or advanced hypertensive retinopathy.
- Endocrinology: for uncontrolled diabetes.
- Cardiology: if severe hypertension is present.