Retinal Vein Occlusion Flashcards Preview

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Flashcards in Retinal Vein Occlusion Deck (33):
1

Arteriolosclerosis

Causative factor for branch retinal vein occlusion 
BRVO 

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Pathogenesis of Retinal Vein Occlusion? 

1. Causative factor for branch retinal vein occlusion 
BRVO = Arteriolosclerosis

2. Arteriole and its corresponding vein share a common connective sheath

⇒Thickening of arteriole → Compress vein 

3. Central retinal vein & artery share a common sheath at arteriovenous crossings posterior to lamina cribrosa 

4. Atherosclerotic changes of the artery may compress vein → Cause Central Retinal Vein Occlusion ( CRVO) 

  • Both arterial and venous disease → Retinal Vein occlusion 
  • Venous occlusion = Increased Venous and cappilary pressure + Decreased blood flow 

 

 

 

 

 

 

 

3

Prediposing factors? 

  • Age 
  • Hypertension: Most prevalent in BRVO ( as site of obstruction @ arteriovenous crossing) 
  • Hyperlipidaemia ( >6.5mmol/l) 
  • Diabetes 
  • Raised IOP ( increased CRVO risk) 

4

Classification of BRVO?

  • First order temporal branch at the optic disc (a) 
  • First order temporal branch away from the disc but involving the branches to the macula (b) 
  • Peripheral BRVO not involving the macular circulation (d, e, f)

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Diagnosis of BRVO?

Symptoms?

 

  • Symptoms depend on the amount of macular drainage compromised by the occlusion 
  • Patients with macular involvement often present with sudden onset of blurred vision and metamorphopsia (distort vision)  or a relative visual field defect 

 

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7

BRVO Diagnosis 

Signs on fundus?

  • Dilatation
  • and tortuosity of the venous segment  (away from the site of occlusion
  • and attenuation near the occlusion 
  • Flame-shaped and dot-blot haemorrhages, retinal oedema, and sometimes cotton-wool spots affecting the sector of the retina drained by the obstructed vein 

8

Signs?

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 BRVO
Tutorsity of vessels 

Vessels present in macula that shouldn't be

9

BRVO- FFA Signs?

 

  • variable delayed venous filling 
  • blockage by blood 
  • hyperfluorescence 
  • hypofluorescence 

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10

Course and Prognosis

of BRVO?

  1. Acute features take 6-12 months to resolve and may be replaced by: 
  • hard exudates 
  • venous sheathing and sclerosis peripheral to the site of obstruction 
  • slightly tortuous vessels
  1. Eventual visual recovery depends on: 
  • amount of venous drainage involved by the occlusion 
  • severity of macular ischaemia 

11

Old BRVO?

Affected the superior BRV 

– Hard exudates 

– Venous sheathing 

– Residual haemorrhages 

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12

Types pf CRVO?

  • Ischaemic 
  • Non-ischaemic 

 

13

Non- ischaemic CRVO?

Signs?

Vision defect?

Fundus appearance?

  1.   Sudden, unilateral blurred vision. 
  2. Afferent pupillary defect (APD) is absent or mild
  3. Fundus shows 
  • Tortuosity and dilatation of all branches of the central retinal vein 
  • Dot-blot and flame-shaped haemorrhages ( 4 quadrants, most numerous in periphery) 
  • Cotton-wool spots
  • Oedema of optic disc and macula 

 

 

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Non-Ischaemic CRVO 

Prognosis

Vision/ Visual Acuity?

  • good if not become ischaemic 
  • Chronic macular oedema → Poor vision 
  • Prognosis - related to initial visual acuity: 

›6/18 or better, it is likely to remain 

›6/24-6/60, the clinical course variable- improve, remain the same, or worsen 

›Worse than 6/60, improvement is unlikely 

 

15

Ischaemic CRVO 

 

  •  Sudden & severe vision loss 
  • Significant APD ( Afferent Pupil Defect) 
  • Fundus: 

–Severe tortuosity 

–Engorgement of all branches of the vein 

–Dot-blot & flame haemorrhages 

–Disc oedema 

–Cotton wool spots 

 

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16

Artery occlusion

Common causes?

  1. Thrombosis/blood clot / Vessel blocked → Prevent perfusion 
  2. Carotid embolism ( From ICA) 
  • Cholesterol 
  • Calcific 
  • Fibrin platelet 

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18

BRAO 

Visual field loss pattern?

VA?

Fundus appearance?

FFA ( Fundus Fluorescein Angiography) ? 

  • Sudden altitudinal/sectoral visual field loss 
  • VA varies 
  • Fundus: 

–Narrow arteries & veins 

–Cloudy white retina (c/b oedema) 

–Emboli can be present 

  • FFA: 

–Delay in arterial filling 

 

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19

BRAO

Prognosis?

  • Poor prognosis unless obstruction can be relieved within a few hours 
  • VF defect = permanent 
  • Affected artery remains attenuated 

 

20

CRAO 

Central Retinal Vein Occlusion?

Vision?

Afferent Visual Defect (APD) ?

Fundus?

  • Sudden, severe vision loss 
  • APD is severe 
  • Fundus
    Similar to BRAO but severe 
    Narrow arteries & veins 
    Cloudy white retina (c/b oedema) 
    Emboli can be present 
    Orange reflex from intact choroid stands out in contrast to surrounding pale retina = cherry red spot 

 

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21

CRAO 

Prognosis?

 

  • Poor prognosis due to retinal infarction 
  • Cloudiness of retina & cherry red spot disappear 
  • Arteries remain attenuated 
  • Retinal atrophy = ↓ VA 

22

Cilioretinal Vein Occlusion 
What is it?

What does it supply?

Cilioretinal artery 

  • present in 20% of the population 
  • arises from the posterior ciliary circulation 
  • supplies the macula and papillomacular bundle 

 

23

Types of Cilioretinal Artery Occlusion?

3 types?

  1. Isolated 
  2. Combined with CRVO 
  3. Combined with anterior ischaemic optic neuropathy ( eg. Giant cell arthritis) 

24

What type of Cilioretinal A. Occlusion?

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Isolated 
Present of haemorrhage 

Papillomacular bundle occluded 

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What type of Cilioretinal A. Occlusion?
Signs ?

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  • Combined with CRVO 
  • Diffuse vessels 
  • Diffuse optic disc
  • Paler area temporally 
  • Tortuosity of vessels 
  • Exudate/ harmorrage 

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What type of Cilioretinal A. Occlusion?

  • Combined with aneterior ischaemic optic neuropathy 

27

 Cilioretinal A. Occlusion
​Symptoms?

Fundus signs?

  • Acute, severe loss of central vision
  • Fundus signs: 
    Cloudiness localized to that part of the retina normally supplied by the vessel 

 

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28

Hypertensive Retinopathy?

 

  • Retinal vascular changes related to microvascular damage from ↑ BP 
  • Retinal arterioles narrow (vasoconstriction) in response to the ↑ BP 
  • Disrupts the inner blood-retinal barrier 

 

29

Hypertensive Retinopathy?

3 Fundus signs?

 

  • Narrow arterioles 
  • Vascular leakage 
  • Arteriosclerosis 

 

30

Arteriolar narrowing 

  • Can be focal or generalised 
  • Hard to diagnose on ophthalmoscopy - may need OCT 
  • Presence of narrowing most likely = hypertension 
  • Severe hypertension can result in cotton-wool spots (sign of occlusion)  

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31

Vascular leakage 

  • Flame-shaped haemorrhages and retinal oedema 
  • Chronic oedema = hard exudates at the fovea (macular star) 
  • Swollen ON head = sign of hypertension 

 

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32

 

Arteriosclerosis ?

 

  • Vessel wall thickens 
  • Changes at arteriovenous crossings (AV nipping) 
  • Arteriosclerosis is graded in terms of severity 

 

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33

Arteriosclerosis grading?

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