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Hypertensive Retinopathy

Introduction

Hypertension is caused by a number of factors, but primarily increased cardiac output either from increased heart rate or stroke volume, as well as an increased vascular resistance, due to blood viscosity, BV length, vasoconstriction.
- This increases the risk of blockage, ischaemic stroke and rupturing to form a haemorrhagic stroke
- Normal BP is around 120-129/80-84
- High normal = 130-139/85-89
- Grade 1, mild hypertension = 140-159/90-99
- Grade 2, moderate hypertension = 160-179/100-109
- Grade 3, severe hypertension = over 180/110
- Emergency = 220/140 --> indicative of organ dysfunction and damage

Dead Giveaways

Chronic Hypertensive Retinopathy

  • A systemic condition characterised by a diagnostic trio:

  • Arteriolar narrowing is first seen in hypertension, as the lumen diameter reduces due to hvasospasm and increased vascular tone from chronically increased BP

    • This is more pronounced in younger patients due to the vessels being less rigid

  • Copper and Silver wiring is used to describe the increased retinal arterial light reflect, as the lighting appears whiter than usual.

    • Due to the atherosclerotic changes that occur, the thickening of the vessels and hyaline degeneration leads to opacification

  • AP Nipping refers to the indentation or narrowing of a vein due to an overlaying arteriosclerotic artery

    • Aforementioned silver wiring can be seen in the borrom right, and AP nipping seen in the top. Note that the arteries look very narrow.
      Aforementioned silver wiring can be seen in the borrom right, and AP nipping seen in the top. Note that the arteries look very narrow.

Acute Hypertensive Retinopathy:

  • Can occur due to breakdown of vascular auto-regulatory mechanisms

  • Characterised by a diagnostic trio:

  • Retinal Haemorrhages can include flame and blot/dot, due to the disruption of the iBRB due to hypertensive vascular changes, allowing the exudation of blood and plasma into the retina, and thus causing haemorrhaging and hard exudates

  • Hard Exudates take on a unique shape called the macular star, in which it radiates outwards like a star

  • Cotton Wool is a result of focal ischaemia

    • Note the central macular star, the cotton wool spot near the optic disc, and the flame haemorrhages underneath.
      Note the central macular star, the cotton wool spot near the optic disc, and the flame haemorrhages underneath.

Malignant Hypertensive Retinopathy:

  • Characterised by BP of over 180/120 mmHg, and is considered a medical emergency

  • Arterial attenuation, widespread exudates, macular star are all present

  • Most prominent feature is on Fundus:

    • Note the acute features here, but also the significantly more blurry and indistinct optic disc edges
      Note the acute features here, but also the significantly more blurry and indistinct optic disc edges

    • Papilloedema can occur, and the optic nerve is elevated, which is much better appreciated in 3D, but the blurring of the margins, indicates elevation.

    • This can progress rapidly to increase intracranial pressure as well

    • Can be confirmed with RNFL thickening at the ONH

diagnostic features

Mitchell-Wong Classification of Hypertensive Retinopathy

Mild: -> Generalised arteriolar narrowing, focal arteriolar narrowing, arteriovenous nicking, copper wiring or combination

Moderate: -> Retinal haemorrhages (blot, dot, flame), MA, CWS, hard exudates, or combination

Malignant: -> Signs of moderate but with disc swelling


Risk Factors:

Primary Hypertension

  • Obesity, diet, insulin resistance, salt uptake

  • Stress and depression

  • Genetics

  • Obstructive sleep apnoea

  • Sedentary lifestyle

  • Sympathetic overactivity

Secondary Hypertension

  • Kidney disease

  • Endocrine conditions

  • Pre-eclampsia in 2nd half of pregnancy

    • Due to high BP, fluid retention and proteinuria. Can be fatal for both baby and mother

    • Asymptomatic, or associated with symptoms such as nausea, vomiting, severe headaches, abdominal pain and swelling of face, hands. and legs


Signs and Symptoms:

  • Usually asymptomatic, and can only be detected in examination

  • Assuming no papillodema, communicate with GP. If papilloedema, it is an emergency

  • If they do show:

    • Headaches, usually occipital and in the morning

    • Lightheadedness

    • Vertigo

    • Tinnitus

    • Altered vision

    • Fainting


Moderate BP:

  • Most important preventable risk factor for CVD and death

  • Can cause coronary artery disease, ischaemic heart disease and congestive cardia failure, strokes, pulmonary embolism and peripheral vacular disease

  • In the eye, causes hypertensive retinopathy and choroidopathy

  • Can also lead to renal failure, cognitive decline and dementia


Extremely High BP:

  • Characterised by 220/140

  • May include heart failure, pulmonary attack, heart attack, aortic aneurysm, renal failure, stroke

  • May include papilloedema

  • Consistutes an ocular emergency

2025, made by Eric Qin. UNSW. SOVS

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