SN3 SHORT NOTE 5M ★ High-yield

Describe hypertensive retinopathy and the other systemic retinopathies.

Ophthalmology · 3rd Professional

The retinal circulation is the only part of the systemic circulation that can be observed directly.
The retinal response to raised pressure has four components: vasoconstriction (autoregulatory narrowing, seen in the young elastic vessel); arteriosclerosis (chronic wall thickening, seen in sustained hypertension); exudation (breakdown of the blood-retinal barrier, giving haemorrhages, exudates and oedema); and ischaemia (cotton-wool spots)

KEITH-wagener-BARKER grade	Findings
Grade I	Mild generalised arteriolar narrowing and increased light reflex
Grade II	Definite focal narrowing and arteriovenous nipping at crossings. Increasing light reflex gives copper-wire and then silver-wire arterioles
Grade III	Grade II plus flame haemorrhages, cotton-wool spots and hard exudates.
Grade IV	Grade III plus optic disc oedema. This defines malignant (accelerated) hypertension and is a medical emergency

Named crossing signs — SALUS sign, deflection of the vein at the crossing; GUNN sign, tapering of the vein on either side; and bonnet sign, banking and dilatation of the vein distal to the crossing. These crossings are the sites of branch vein occlusion
Hypertensive choroidopathy — seen in acute severe hypertension, particularly in young patients, pre-eclampsia and phaeochromocytoma: elschnig spots (patches of pigment epithelial infarction) and siegrist streaks (linear pigmentation along choroidal vessels), with exudative retinal detachment, which resolves as the pressure is controlled
Grade III and IV disease require urgent medical referral, since they indicate end-organ damage and carry a high mortality if untreated

Condition	Retinal features
Anaemia	Pale fundus, haemorrhages and cotton-wool spots; ROTH spots — white-centred haemorrhages, the centre being fibrin and cellular debris. Roth spots are not specific to endocarditis, occurring also in anaemia, leukaemia and diabetes
Leukaemia	Haemorrhages, Roth spots, venous dilatation, and leukaemic infiltration of the choroid and optic nerve. A pseudohypopyon of leukaemic cells may occur, and infiltration of the optic nerve is an emergency requiring radiotherapy
Sickle cell disease	Proliferative retinopathy commoner in HbSC and HbS-thalassaemia than in HbSS. Sea fan neovascularisation, salmon patch haemorrhages, black sunbursts and comma-shaped conjunctival vessels
HIV	HIV retinopathy with cotton-wool spots is the commonest finding and is non-infective; cytomegalovirus retinitis at CD4 below 50; and other opportunistic infections
Bacterial endocarditis	Roth spots and septic emboli; and rarely endogenous endophthalmitis
Pregnancy and pre-eclampsia	Hypertensive changes, choroidopathy and exudative detachment; and progression of pre-existing diabetic retinopathy
Radiation retinopathy	Resembles diabetic retinopathy, appearing months to years after radiotherapy to the head and neck
Drug toxicity	Hydroxychloroquine causing a bull’S eye maculopathy.

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