hypertensive retinopathy

Hypertensive Retinopathy

Hypertensive Retinopathy

• Prevalence

• Symptoms

• Diagnostic techniques and signs

• Pathophysiology

• Associated conditions

• Management

Hypertensive Retinopathy - Introduction

• Bilateral

• Symmetrical

• Small blood vessel disease

• Caused by systemic hypertension– Acute or chronic– Systolic or diastolic

• End organ disease manifestation

Hypertensive Retinopathy - Prevalence

• The second most common retinal vascular disease

• Systemic hypertension (>160/90mmHg) 10-15% in the UK >40 age group

• Malignant hypertension (240/140mmhg)0.5-0.75%

• Hypertensive retinopathy 4-10%

Hypertensive Retinopathy – Prevalence, Risk factors

• Afro-Caribbeans = relative risk factor 2x• Age• Family history• Medications• Obesity• Smoking• Stress• Alcohol consumption• Lack of exercise

Hypertensive Retinopathy – Prevalence, Morbidity Risk

• Stroke (7x)

• Heart attack (4x)

• Coronary artery disease (3x)

• Peripheral artery disease (2x)

Hypertensive Retinopathy – History & Symptoms

• Possible history of systemic hypertension

• Systemic hypertension largely asymptomatic

• Hypertensive retinopathy largely asymptomatic

• The eye examination will often give the first clue of systemic hypertension

Hypertensive Retinopathy – Diagnostic Techniques & Signs

• Ophthalmoscopy (non-malignant retinopathy)– Arteriosclerosis from chronic disease

• focal arteriolar narrowing• arterio-venous crossing changes

– venous constriction and deflection– distal banking

• arteriolar colour changes• vessel sclerosis

– Similar signs with ageing

• Sphygmomanometry– blood pressure measurement is required to make a positive

diagnosis in the absence of malignant retinopathy changes

Hypertensive Retinopathy – Diagnostic Techniques & Signs

• Arteriolar Narrowing– Young patients, autoregulation causes uniform

narrowing of retinal arterioles

– Older patients, arteriosclerosis and autoregulation cause focal arteriolar narrowing

– Assess the arterio-venous calibre ratio as a percentage• adjacent arteries and veins

• equivalent numbers of bifurcations

• between 1 and 3 DD from optic disc

Hypertensive Retinopathy – Diagnostic Techniques & Signs

Generalised narrowing of the retinal arterioles

Hypertensive Retinopathy – Diagnostic Techniques & Signs

Focal narrowing of the retinal arterioles – Copper and Silver Wiring

Hypertensive Retinopathy – Diagnostic Techniques & Signs

• Tortuosity of the retinal arterioles – not, in itself, a sign of hypertensive retinopathy– segmental arteriolar tortuosity is such a sign

• commonly found in the nasal retina

– Almost 80% of patients with hypertension do not show tortuosity

– A standard 5 point grading scale can be used– Record tortuosity type, severity and location

Hypertensive Retinopathy – Diagnostic Techniques & Signs

• Arteriosclerosis– Thickening of the arteriolar wall

– Assess using the arteriolar reflex• brightness

• thickness ratio

– Assess using arterio-venous crossing changes• venous deflection (Salus’ sign)

• localised venous narrowing (nipping; Gunn’s sign)

• right-angled crossing caused by venous deflection

• venous distal banking (Bonnet’s sign)

Hypertensive Retinopathy – Diagnostic Techniques & Signs

Gunn’s sign & right-angled crossing

Bonnet’s sign

Hypertensive Retinopathy – Diagnostic Techniques & Signs

Gunn’s sign, right-angled crossing & Bonnet’s signSalus’ sign?

Hypertensive Retinopathy – Diagnostic Techniques & Signs

• Malignant Hypertensive Retinopathy– A:V ratio of 25% & arterial reflex ratio of 60%

• “copper wiring”

– A:V ratio of <20% & arterial reflex ratio of 100%• “silver wiring”

– cotton wool spots– hard exudates– dot and flame shaped haemorrhages– if advanced – retinal or macula oedema or papilloedema– all non-advanced changes due to focal hypoperfusion– note presence, number, size, position (photograph!)

Hypertensive Retinopathy – Diagnostic Techniques & Signs

Early malignantDot and blot haemorrhagesHard and soft exudatesDiffuse arteriolar narrowingArterio-venous crossing defects

Hypertensive Retinopathy – Diagnostic Techniques & Signs

Advanced malignantMacular starPailloedema

Hypertensive Retinopathy - Classification

Grade DescriptionAlternative description

A:V ratio

Iminimal narrowing of the retinal arteries Non-malignant 50%

IInarrowing of the retinal arteries in conjunction with regions of focal narrowing and arterio-venous nipping

Non-malignant 33%

IIIabnormalities seen in Grades I and II, as well as retinal haemorrhages, hard exudation, and cotton-wool spots

Malignant 25%

IVabnormalities encountered in Grades I through III, as well as swelling of the optic nerve head and macular star

Malignant <20%

Hypertensive Retinopathy – Classification Grade 2

Hypertensive Retinopathy – Classification Grade 3

Hypertensive Retinopathy – Classification Grade 4

Hypertensive Retinopathy – Classification

• HR grades I and II are typically chronic

• HR grades III and IV are typically acute– diastolic blood pressure >= 110 correlates with

grade III– diastolic blood pressure >= 130 correlates with

grade IV

Hypertensive Retinopathy – Choroidopathy

• Hypertensive choroidopathy frequently occurs with grade IV Hypertensive Retinopathy– yellow spots (Elshnig Nodules) are visible at the level of the

retinal pigment epithelium– hyperfluorescent on fluorescein angiography– secondary to arteriosclerosis within the choriocapillaris– in severe cases they cause serous retinal detachment– resolve to become pigmented or depigmented– linear groups of spots occur they are referred to as Siegrist's

streaks

Hypertensive Retinopathy – Pathophysiology

• A disease of the retinal microvasculature• Cholesterol deposition in the tunica intima of

medium and large arteries– reduction in the lumen size of these vessels

• Arteriolosclerosis causes a breakdown in autoregulation– the high pressures in the arterioles are transmitted to

the retinal capillaries

– capillary closure or haemorrhage occurs

Hypertensive Retinopathy – Pathophysiology

• Dot haemorrhages are ruptures of the deep capillary bed– leakage of blood into the outer plexiform layer – their depth leads to a round, small area of blood– Phagocytosis of the red and white blood cells leaves

hard exudates– the hard exudates are at a similar depth and have a

similar size (slightly larger) and shape to the dot haemorrhages

– hard exudates will last for more than 12 months, even following successful treatment.

Hypertensive Retinopathy – Pathophysiology

• Flame shaped haemorrhages are ruptures of the superficial capillary bed– the blood disperses within the retinal nerve fibre layer

• Either capillary rupture or capillary closure gives:– RGC oxygen starvation– RGC waste removal failure– Axoplasmic transport failure

• accumulation of waste material at the boundary between perfused and non-perfused retina

• clinically visible as cotton wool spots (CWS)

• In extreme cases, disc oedema– a hypertension-related increase in intracranial pressure

Hypertensive Retinopathy – Pathophysiology

• Arteriosclerotic changes persist after Tx• Hypertensive retinopathy changes resolve over time

following Tx– Cotton wool spots develop in 24 to 48 hours with the elevation

of blood pressure, and resolve in 2 to 10 weeks– A macular star develops within several weeks of the

development of elevated blood pressure and resolves within months to years

– Papilloedema develops within days to weeks of increased blood pressure and resolves within weeks to months

– Visual recovery is limited if the macula or optic nerve have been affected

Hypertensive Retinopathy – Management

• Appropriate treatment of the underlying hypertension• If the patient is previously undiagnosed the patient

needs referral to their general practitioner for assessment• A grade I or grade II hypertensive retinopathy

– non-urgent referral

• A grade III hypertensive retinopathy – more urgent referral to the GP

• A grade IV hypertensive retinopathy – Px is in medical crisis. This patient needs immediate referral

to a hospital eye casualty department

Hypertensive Retinopathy – Associated Conditions

• Branch retinal artery occlusion (BRAO)

• Central retinal artery occlusion (CRAO)

• Branch retinal vein occlusion (BRVO)

• Central retinal vein occlusion (CRVO)

• Non-arteritic anterior ischaemic optic neuropathy (NAION)

Hypertensive Retinopathy – Clinical Pearls

• If CWS are present, autoregulation has failed: diastolic BP >110mmHg

• Papilloedema means malignant hypertensionBP > 250/150mmHg

• Fluorescein angiography is not indicated as it provides no diagnostic information

Hypertensive Retinopathy – Clinical Pearls

Hypertensive Retinopathy Diabetic Retinopathy

Dry retina:

few haemorrhages

rare oedema

rare exudate

multiple cotton wool spots

flame-shaped haemorrhages

visibly abnormal retinal arteries

Wet retina:

multiple haemorrhages

extensive oedema

multiple exudates

few cotton wool spots

rare flame-shaped haemorrhages

visibly abnormal retinal veins and capillaries