Ophthalmology - Retinal Vein Occlusion

Question 1

What occurs in retinal vein occlusion?

Answer 1

Thrombus forms in the retinal veins, blocking the drainage of blood from the retina

Question 2

Where can the thrombus form in retinal vein occlusion?

Answer 2

Central retinal vein
Branch retinal veins

Question 3

Outline branch retinal vein drainage

Answer 3

Branch retinal veins
Central retinal vein (runs through optic nerve)
Superior ophthalmic vein or cavernous sinus

Question 4

What is the consequence of blockage in the central retinal vein?

Answer 4

Causes problems with the whole retina

Question 5

What happens when a branch retinal vein is blocked?

Answer 5

Affects the area drained by that branch

Question 6

What sites are at higher risk of occlusion?

Answer 6

Areas where retinal arteries cross over the top of veins

Causes narrowing of the vein

Question 7

What is the result of blockage of a retinal vein?

Answer 7

Venous congestion in the retina

This causes an increasde prsesure which leads to fluid and blood leaking into the retina

Resulting in macular oedema and retinal haemorrhages

Question 8

What are the two categories of retinal vein occlusion?

Answer 8

Ischaemic
Non-ischaemic

Question 9

What does retinal ischaemia lead to?

Answer 9

Release of vascular endothelial growth factor (VEGF) and new blood vessel development (neovascularisation)

Question 10

What are the risk factors for retinal vein occlusion?

Answer 10

• Hypertension
• High cholesterol
• Diabetes
• Smoking
• Hyperviscosity (myeloma)
• Myeloproliferative disorders
• Inflammatory conditions

Question 11

What key symptom can identify retinal vein occlusion?

Answer 11

Painless blurred vision or vision loss

Question 12

In branch retinal vein occlusion, what does the vision loss correspond to?

Answer 12

The affected area of the retina

When the branch draining the macula, central vision is lost

Question 13

What are the characteristic findings in fundoscopy for retinal vein occlusion?

Answer 13

• Dilated tortuous retinal veins
• Flame and blot haemorrhages
• Retinal oedema
• Cotton wool spots
• Hard exudates

Question 14

What does the fundus in retinal vein occlusion resemble?

Answer 14

Characteristic ‘blood and thunder’ appearance

Question 15

What is a potential confusion with the appearance of retinal vein occlusion?

Answer 15

The ‘pizza pie’ appearance of cytomegalovirus (CMV) retinitis

Question 16

How is retinal vein occlusion managed?

Answer 16

Suspected RVO should get immediate referral to ophthalmology

Treat macular oedema and prevent neovascularisation

Question 17

How is retinal vein occlusion treated?

Answer 17

• Anti-VEGF therapies (e.g., ranibizumab and aflibercept)
• Dexamethasone intravitreal implant (macular oedema)
• Laser photocoagulation (treats new vessels)