Vascular Occlusions Flashcards
What is the second most common retinal vascular disease?
RVO (retinal vein occlusions)
What is more common BRVO or CRVO?
BRVO
Why does a BRVO happen?
Venous compression by an artery which causes turbulent blood flow, endothelial damage and then thrombosis —> OCCLUSION
What is the main age occurrence of BRVOs?
60 years
What are some RF of BRVO?
- Systemic HTN
- DM
- smoking
- cardiovascular disease
- glau history
- previous RVO in either
- inflammatory condition
What is a protective factor of BRVO ?
Vein crosses artery instead of artery crossing a vein
What are symptoms of BRVO?
- Sudden painless loss of vision
- Can be asymptomatic
- If macula covered, sector field defect
Where are 66% of cases of BRVO on the retina ?
Superior temporal
In an acute stage of BRVO, what will you observe ?
- Flame haemorrhages
- dilated and tortuous veins
- retinal oedema
- CWS
- normally respect the horizontal mid line
What signs may you see with a px who has chronic stage BRVO?
- hard exudates
- vascular sheathing (appearing white)
- macula pigment
- collateral vessel formation
- retinal ischameia
What is collateral vessel formation?
Small, tortuous vessels that cross horizontal line to drain into unaffected quadrant
Where would retinal ischaemia occur in chronic BRVO?
Downstream to the occlusion
What does retinal ischaemia result due to BRVO?
Upregulation of VEGF + increased vessel permeability + macula oedema
Is this a chronic or acute stage BRVO?
Chronic (substantial amount of exudate)
What can you note that is similar in these two pictures in relation to the BVs?
Vascular sheathing (that white appearance)
What is the main cause of visual loss in BRVO?
Chronic macula oedema
What is an epiretinal membrane?
A membrane forming on the surface of the retina
What are six complications of BRVO?
- Chronic macula oedema
- Exudates
- Haemorrhages
- Epiretinal membrane
- neovasc
- RD (rare)
Why does neovasc occur?
Unregulation of VEGF
When would neovasc occur in BRVO?
ONLY if a large area of retina id ischameic
What type of RD will occur even though it is rare?
Tractional or rhegmatogenous
How long would it take macula oedema to resolve?
12 months in 40% if cases
What % of eyes will maintain a va <6/12?
50%
What % of eyes will have a va <6/60?
25%
Is neovasc glaucoma rare with BRVO?
Yes
After having BRVO in one eye, what %h have it in the other eye?
10%
Is retinal neovasc rare with BRVO?
YES
What causes CRVO?
Thrombus formation (blood clot) where the central artery and central vein leave the nerve head at the lamina cribosa
What are three possible mechanisms for CRVO?
- Arteriosclerosis of CRA disturbing blood flow in vein
- Mechanical pressure in lamina cribosa
- Vessel wall or blood changes
Name some RF of CRVO
- Systemic HTN
- DM
- OAG
- cardiovascular disease
- systemic inflammatory conditions
What is the acute presentation of CRVO? symptoms
- sudden onset vision loss
- painless
- RAPD present
- photos potentially
What is known to describe a CRVO?
BLOOD AND THUNDER
What signs would you see on a CRVO fundus?
- Retinal haemorrhages
- dilated tortuous veins
- CWS
- macula oedema
- unilateral optic disc oedema
What are the two types of CRVOs?
Ishaemic and non-ischaemic
What % of CRVOs are ischaemic ?
20%
On Fluorescein angiography, what would you see with an ishaemic CRVO?
Fluorescein not permeating to Large areas of retinal capillaries —> this is causing the ischaemia due to lack of blood supply
(In the pic right is a normal eye)
What are signs if an ischaemic CRVO?
- Severe vision loss
- RAPD
- Multiple intraretinal haemorrhages
- CWS
- optic disc swelling
In Relation to FA, what classifies an ischaemic CRVO?
Area of non-perfusion (where the Fluorescein fails to get to) is greater than 10 DD
What % of CRVO does non-ishaemic CRVO account for?
80%
Where are the haemorrhages + what type of haemorrhages are common with CRVO?
Superficial flame
What is different in non-ischaemic CRVO compared to ishaemic?
- superficial flame haemorrhages
- va is better
- fewer CWS
What is different in non-ischaemic CRVO compared to ishaemic?
- superficial flame haemorrhages
- va is better
- fewer CWS
What are complications of CRVO?
- ishaemia
- upregulation of VEGF
What can an up regulation of VEGF lead to in CRVO?
- Macula oedema
- NVD
- NVE
- Vitreous haemorrhage
- Neovasc glaucoma
In chronic compensation cases of CRVO, what do we tend to see in relation to the haemorrhages?
A re absorbtion (flame first , then dot and blot )
What can develop to divert retinal blood to choroidal circulation ?
Optociliary shunt vessels
What is a DD of chronic compensation after CRVO?
Diabetic retinopathy as you are left with deeper dot and blot haemorrhages
In non-ishaemic CRVO what % of eyes does macula oedema resolve?
30%
Is neovasc glaucoma rare in non-ishaemic CRVO ?
Yes
What can a poor VA caused by CRVO mean?
Poorer VA prognosis
True or false:
80% of eyes with VA <6/60 at presentation of CRVO will no improve over time
True :(
What % of eyes with Visio <6/60 will develop rubeosis iridis?
44%- they need to be followed up by an ophthalmologist
What are two that must be considered when managing CRVO or BRVO?
1) managing underlying cause
2) ophthalmic implications such as macula oedema, NVE, neovasc glaucoma
What must you do in ALL cases of CRVO and BRVO?
Refer to GP for investigation AND Refer to be seen by an ophthalmologist within 2-4weeks of presentation
But look at local referral schemes
If px has neovasc glaucoma, what should you do?
Phone eye department for triage
What is the treatment for NVE?
Laser pan-retinal photocoagulation
What does Laser pan-retinal photocoagulation Do?
Reduce hypoxia and VEGF production by reducing O2 demand of photoreceptors and RPE
What is neovasc glaucoma caused by?
New vessels on iris or angle which blocks drainage
What is the aim when treating neovasc glaucoma if eye is blind?
Keep eye pain free with topical steroids and atropine
What is treatment when Treating neovasc glaucoma if there is vision?
Control IOPs with anti-glaucoma drops. Or/amd surgery
What referral is required for undiagnosed neovasc glaucoma?
UGRENT (if pressure is >40mmHg then is an emergency)
What is commonly used to treat macula oedema in CRVO which causing vision loss?
Anti-VEGF (Lucentis or Eyelea) or dexamethasone (steroid)
Which types of px is Anti-VEGF preferred in?
Previous history of glaucoma, younger px who are phakic
Which types of px would you want to use a steroid to treat macula oedema?
Recent cardiovascular events + px who do not favour monthly injections
What is the main cause of CRAO?
Embolus from atherosclerosis (like plaque that breaks off) and lodges in a narrow part of CRA
What are some RF of CRAO?
- HTN
- DM
- tobacco use
- renal disease
- atherosclerosis
- TIA
- GCA
- Lupus
What is a px at risk of if they have CRAO or BRAO?
Life-threatening cardiovascular/cerebrovascular incident
Why is CRAO and BROA so serious?
They have these emboli floating around their blood which can get jammed anywhere in the body, INCLUDING THE BRAIN
What is the presentation of someone with CRAO or BRAO?
-SUDDEN painless loss of vision
-May have a history of amaurosis fugax
-Mean age of 60 yrs
In 90% of cases what vision would someone with CRAO or BRAO have ?
Counting Fingers (CF) or Light Perception(LP)
What is amaurosis fugax?
Transient loss of vision lasting 2 seconds- 2 hours
What would the fundus look like with someone with an acute BRAO and CRAO?
- Oedematous, milky opaque Retina
- Cherry red spot
- Segmented BV
Why would an opacity be greatest where the macula is?
The NFL and retinal ganglion cell layer is thickest here
Why is there a cherry red spot?
Fovea blood supply is the choroidal circulation + retina is thinnest here
Why are segmented bV seen?
Blood is moving sluggishly
What would someone with a chronic BRAO OR CRAO fundus look like?
- retinal opacification
- attenuated retinal arterioles
- optic nerve atrophy
- RPE mottling
- homogeneous scar
What does retinal opacification that has resolved 4 weeks result in?
Ischaemic necrosis
Where has a glistening yellow cholesterol emboli come from?
Atherosclerotic plaques from the carotid artery
Where has calcific emboli come from? And how do they look?
Cardiac valves + non-glistening platelet
Where ate Calcific emboli more commonly found?
At the optic disc
What is the name of the glistening yellow cholesterol emboli?
Hollenhorst plaque i
Can emboli dislodge?
Yes, if so a px would have experience amaurosis fugax
If an embolus is trapped does that necessarily mean there is no blood flowing?
No- it may just reduce blood flow
REQUIRES URGENT REFERRAL
What is the management for a px with retinal emboli or history of transient painless vision loss?
Urgent referral for cardiovascular assessment
What is the outcome of CRAO or BRAO?
Severe vision loss
If there is any spontaneous recovery in vision, when would that be?
In the first 7 days
What is the outcome of a BRAO or CRAO if a px has a cilioretinal artery ?
80% will return with a VA of 6/7.5 or better
What is a long term complication of CRAO or BRAO?
Retinal or anterior eye neovasc
What is management of CRAO or BRAO?
SAME DAY EMERGENCY
In practice what can you do/advise if they have a CRAO or BRAO?
- ask px to lie flat
- ocular massage
- ask px to breathe into a paper bag
KEY THING TO DO IS GET THEM TO HOSPITAL
What does lying flat do?
Raises pressure on ophthalmic artery
How is an ocular massage carried out?
Press on the eye with heel of hand, 10 seconds on 10 seconds off for 5 mins
What does breathing into a paper bag do?
Increase co2 levels which can cause vasodilation
What is the window for vision improvement?
4 hours
What are px who have BRAO and CRAO at risk of ?
Heart attack or stroke therefore urgent referral for a medical assessment even if window for vision restoration has passed
Is the visual outcome worse or better for someone with A-AION which has caused arteritic CRAO/BRAO?
WORSE!- URGENT referral
How does an ophthalmologist aim to increase perfusion?
Reduce IOPs or causing vasodilation
What are some ways IOP is reduced for CRAO and BRAO treatment?
- intravenous acetazolamide
- anterior chamber paracentesis
What is anterior chamber paracentesis?
Insert a needle into AC and withdraw some of the aqueous to reduce pressure
Which drugs will be used to try to break up the embolus?
Fibrinolytic drugs
How is arteritic CRAO due to GCA treated? And why?
High dose systemic steroids to prevent the other eye or other vessels being affected
