eye problems (vasculature)

Question 1

retinal vein occlusion

Answer 1

blood clot (thrombus) forms in the retinal vessels and blocks the drainage of blood from the retina. this causes pooling of blood in the retina and leakage - macular oedema and retinal haemorrhages.

damage to the tissue in the retina and loss of vision

release of VEGF which stimulates neovasculariation

Question 2

central retinal vein

Answer 2

runs through the optic nerve
responsible for draining blood from the retina

four branches of vein

Question 3

how does RVO present?

Answer 3

sudden painless loss of vision

Question 4

risk factors for RVO

Answer 4

Hypertension
High cholesterol
Diabetes
Smoking
Glaucoma
Systemic inflammatory conditions such as systemic lupus erythematosus

Question 5

investigations and diagnosis of RVO

Answer 5

PMHx
FBC (leukaemia)
ESR (inflammatory disorders)
BP (HTN)
serum glucose (diabetes)

fundoscopy:
Flame and blot haemorrhages
Optic disc oedema
Macula oedema

Question 6

how is RVO managed?

Answer 6

refer immediately for ophthalmologist assessment and management

2’ treat macular oedema and neovascularisation

• laser photocoagulation
• intravitezal steroids (dexamethasone intraviteral imlant)
• anti VEGF therapies (ranibizumab)

Question 7

central retinal artery

Answer 7

supplies blood tot he retina

branch of the ophthalmic artery which is a branch of the internal carotid artery

Question 8

what is a retinal artery occlusion?

Answer 8

something blocks the flow of blood through the central retinal artery

most common cause of occlusion is atherosclerosis, GCA (vasculitis causes reduced blood flow)

Question 9

risk factors for retinal artery occlusion?

Answer 9

Older age
Family history
Smoking
Alcohol consumption
Hypertension
Diabetes
Poor diet
Inactivity
Obesity

2’ to GCA 50 y/o female already affecting by GCA / PMR

Question 10

how does RAO present?

Answer 10

sudden painless loss of vision
RAPD (pupil of affected eye constrictions more when light is shone compared to the others

**This occurs because the input is not being sensed by the ischaemic retina when testing the direct light reflex but is being sensed by the normal retina during the consensual light reflex

Question 11

RAO fundoscopy findings

Answer 11

pale retina (lack of perfusion)
cherry red spot (macula which has a thinner surface that shows the red coloured choroid below and contrasts with the pale retina)

Question 12

how should RAO be managed?

Answer 12

immediately to ophthalmologist for assessment and management

(if GCA- ECR and temporal artery biopsy, tx with high dose steroids predniosolone 60mg)

immediate:
occular masage
remove fluid from anterior chamber to reduce IOP
inhale carbon (CO2 and O2 to dilate artery)
sublingual isosorbide denigrate to dilate the artery

long term: risk factors / CVS

Question 13

subconjunctival haemorrhage

Answer 13

one of the small blood vessels in the conjunctiva ruptures and releases blood into the space between the sclera and conjunctiva

episodes of strenuous activity (heavy coughing, weight lifting, straining when constipated, trauma to the eye)

Hypertension
Bleeding disorders (e.g thrombocytopenia)
Whooping cough
Medications (warfarin, NOACs, antiplatelets)
Non-accidental injury

Question 14

how does subconjunctival haemorrhage present?

Answer 14

bright red blood under the conjunctiva and infront of the sclera

painless
does not effect vision
hx of ppt event

Question 15

management of subconjuctival haemorrhage

Answer 15

harmless
resolves spontaneously (two weeks)
lubricating eye drops if there is a foreign body sensation