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Ophthalmology & ENT > Sudden visual loss > Flashcards

Sudden visual loss Flashcards

1
Q

Causes of sudden visual loss?

A

Vascular occlusions: retinal artery or vein occlusions, anterior ischaemic optic neuropathy

Inflammation: optic neuritis

Retinal detachment

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2
Q

Which vessels in the eye can get occluded?

A

Branch retinal artery
Central retinal artery

Branch retinal vein
Central retinal vein

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3
Q

Presentation of retinal arterial occlusions?

A

Sudden
Relative afferent pupillary defect

Central artery: total loss of vision

Branch artery: altitudinal loss (horizontal half)

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4
Q

Pathophysiology of retinal artery occlusion?

A

Caused by:
Atherosclerosis
Emboli from carotid artery or heart
Giant cell arteritis

A blockage of the central retinal artery or one of its branches, causes ischaemia and eventual death of the cells of the retina.

Resulting in permanent loss of vision in the area of retina supplied by the blocked artery

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5
Q

What is origin of the retinal artery?

What are its branches?

A

Branch of ophtalmic artery which is a branch of internal carotid

It divides into two main branches, superior and inferior

These further divide into temporal and nasal

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6
Q

Signs of retinal artery occlusion?

A

Fundoscopy:

  • thin retinal arteries
  • cherry red spot at macula
  • retinal pallor
  • cotton wool spots (retinal infarcts)
  • cholesterol emboli
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7
Q

Investigation of retinal artery occlusion?

A

Fundoscopy

BP and listen for carotid bruits
Carotid doppler

ESR to rule out Giant cell arteritis

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8
Q

Management of retinal artery occlusion?

A

Ocular massage

Manage giant cell arteritis if suspected (steroids)

Surgical removal of vitreous (anterior chamber paracentesis)

Use other pressure lowering drugs: mannitol, beta blockers

Dilation of artery

Manage risk factors: diet, lifestyle

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9
Q

Pathophysiology of retinal vein occlusion?

A

Occlusion in the retinal vein

Caused by thrombus, or diseased vessel wall

Which causes backlog of blood and hypoxia, blood constituents go out into extra-vascular space, leading to further stagnation

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10
Q

Two types of retinal vein occlusion?

A

Branch RVO

Central RVO

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11
Q

Presentation of branch RVO?

A

Painless unilateral blurring of vision

Image distortion

Altitudinal visual field defect

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12
Q

Signs of branch and central RVO?

A

Poor visual acuity

Fundoscopy:

  • vascular dilatation
  • tortuousity of affected vessels
  • arc hemorrhages
  • flame haemorrhages
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13
Q

Management of branch and central RVO?

A

Refer within 24 hours

Laser grid photocoagulation

Intravitreal triamcinolone (steroid suspension)

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14
Q

Causes of branch and central retinal vein occlusion?

A 
Hypertension
Atherosclerosis
Diabetes
Smoking
Thrombophilia
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15
Q

Presentation of central RVO?

A

Sudden unilateral painless visual loss
Or blurred vision
Often on waking

Relative afferent pupillary defect

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16
Q

Types of central RVO? Which is most severe?

A

Non-ischaemic: milder, better prognosis, self-resolves

Ischaemic: more severe

17
Q

Complications of central and branch RVO?

A

Neovascularisation of retina and iris
Which can lead to secondary glaucoma

Vitreous haemorrhage
Macular oedema

18
Q

What is anterior ischaemic optic neuropathy? Two types?

A

Can be arteritic (inflammatory damage to arteries) and non-arteritic (non-inflammatory damage to small vessels)

Damage to optic nerve caused by insufficient blood supply

19
Q

Causes of AION?

A

Giant cell arteritis

20
Q

Investigations of AION?

A

Check for signs + symptoms of GCA

  • ESR
  • CRP
  • temporal artery biopsy

Fundoscopy:
- pale swollen optic disc

21
Q

Presentation of AION?

A

Sudden and profound loss of vision

Relative afferent pupillary defect

22
Q

Management of AION?

A

If its GCA related then give high dose steroids to prevent loss of vision in other eye

23
Q

What is optic neuritis?

A

Inflammation of optic nerve

24
Q

Causes of optic neuritis?

A

Often caused by MS, when it is then called acute demyelinating optic neuritis

Ischaemic optic neuritis

Infections: toxoplasmosis, syphilis

Vit B12 deficiency

Drugs: ethambutol, isoniazid, amiodarone, methanol

25
Q

Presentation of optic neuritis?

A

Triad

  1. Reduced vision
  2. Eye pain (particularly on movement)
  3. Dyschromatopsia - Impaired colour vision (red appears less red)

Also

  • light flashes
  • Uhthoff’s phenomenon
  • Pulfrich’s phenomenon
  • Fatiguing
26
Q

What is:

  • Uhthoff’s phenomenon
  • Pulfrich’s phenomenon
A

Uhthoff’s: worsening of symptoms with raised body temp

Pulfrich’s: altered perception of direction of movement

27
Q

Signs on examination of optic neuritis?

A

RAPD
Decreased visual acuity
Normal disc
Central scotoma

28
Q

Management of optic neuritis?

A

High dose methylprednisolone for 72 hours

Usually recovers after 6-8 weeks, steroids speed this up

Ophthalmology & ENT (14 decks)

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