Download - 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