DIS - Basic Pathology: Vascular I - Week 9 Flashcards
What kind of artery system is the vascular supply to and from the eye? What does this mean for collateral supply?
It is an end-artery system
No collateral supply
List the major arteries leading to the three main ocular arteries (6) beginning with the aorta.
Common carotid Internal carotid Ophthalmic -central retinal artery -short posterior ciliary artery -ciliomacular artery
Where does the central retinal vein drain to? What does that drain to?
Cavernous sinus
Internal jugular
List the two main types of occlusions for arteries and veins (ocular). Can a combination of artery and vein occlusions occur?
Central and branch retinal vein occlusion
Central and branch retinal arterial occlusion
-combined is possible
List the two types of central retinal vein occlusion. List other names they have if applicable (2).
Ischaemic
Non-ischaemic
-partial
-venous stasis retinopathy
List the five types of branch retinal vein occlusions and note whether they are major or minor if applicable.
Hemi-central
1st order (major)
2nd order - after the first crossing (minor)
-macula or peripheral (after the third crossing or more)
-macula or macula sparing
Describe the components of virchows triad and what it leads to. Does it apply only to the retinal vessels?
Altered blood flow
Endothelial injury
Hypercoagulability
Interaction between these three main factors leads to thrombosis
Applies to all other vessels, not just retinal
List four diseases that can cause endothelial damage.
Hypertension
Diabetes
Atherosclerosis
Vasculitis
List two things that can result in venous stasis in the retina.
Glaucoma
Carotid flow
Lidt four things that can cause hypercoagulability.
Lupus anticoagulant
Hyperhomocysteinaemia
Factor V leidin mutation
Protein s or c deficiency
Define central retinal vein occlusion. What landmark does it usually occur at and at what age?
Acute obstruction of the vein lumen
Usually at the lamina cribrosa
Usually >65yoa
What kind of disease is CRVO essentially? Why is this so?
An arterial disease
-shared adventitia of artery and vein
Describe the role of increased IOP in CRVO (3).
Increased IOP
Backward bowing of the lamina
Pressure on the vein
-turbulent blood flow etc
What is the main risk factor for CRVO? List 9 additional risk factors.
Systemic hypertension Age Diabetes Hyperlipidaemia Smoking Obesity Increased IOP Hyperviscosity conditions Thrombophilic disorders Oral contraceptives
What two things can give a moderate decrease to the risk of CRVO?
Physical activity
Moderate alcohol consumption
What percentage of all CRVO cases is ischaemic?
20%
How does ischaemic CRVO affect vision and is pain involved? How quickly is vision lost?
Marked visual loss with no pain
Vision is lost quickly
How does non-ischaemic CRVO affect vision and is pain involved? How quickly is vision lost?
Less obvious vision loss but is painless
Vision is lost more slowly
What percentage of non-ischaemic CRVO cases will convert to ischaemic CRVO?
20%
Is RAPD present with Ischaemic CRVO? What happens with greater ischaemia?
Yes, worse with greater ischaemia
What do the veins look like in ischaemic CRVO?
Dilated and tortuous
Where on the retina would you expect to see haemorrhages with ischaemic CRVO? Especially what region? What kind of haemorrhage (2)?
The entire fundus, especially the posterior pole
Would see dot/blot and flame haemorrhages
List 5 clinical features you would expect to see with ischaemic CRVO.
Dilated/tortuous veins Retinal haemorrhages Retinal oedema Cotton wool spots Optic disc oedema
What can occur later with ischaemic CRVO? What percentage of cases will develop this? How do a and b waves appear on an ERG with this?
Development of new vessels and/or collaterals
ERG - normal a wave, decreased b wave amplitude
35% of cases will develop this
Is RAPD present with non-ischaemic CRVO?
It may or may not be present
How do veins generally appear in non-ischaemic CRVO?
Variable, dilated, tortuous
What are haemorrhages like with non-ischaemic CRVO? In what region are they worse and what types would you expect to see (3)?
Scattered, variable number
Worse in the periphery
Dot/blot/flame haemorrhages
Is there retinal oedema with non-ischaemic CRVO? What about optic disc oedema?
Yes to both
Is new vessel growth likely with non-ischaemic CRVO? What is the ERG like?
New vessels less likely
ERG normal?
What can CRVO be confused with?
Diabetic retinopathy
List three features of angiography in ischaemic CRVO. Where would you expect to see staining? Where especially would you expect to see leakage (2)?
Delay in filling
Leakage (especially at the macula and disc)
Capillary non-perfusion
Staining of the vein wall
Compare angiography in non-ischaemic CRVO to ischaemic CRVO (2).
Smaller
Capillary non-perfusion
List five differential diagnoses for CRVO.
Severe diabetic retinopathy Ocular ischaemic syndrome Retinitis Coats disease Benign intracranial hypertension -pseudotumour cerebri
What percentage of untreated CRVO gets better and worse?
10-20% improves
35-50% gets worse
Within what timeframe do most acute signs of CRVO resolve?
Over 9 to 12 months
List 5 residual signs that may be left over with CRVO.
Haemorrhage Disc collaterals Sheathing of blood vessels Pre-retinal fibrosis/epiretinal membrane Macular pigmentary changes
What will develop in 50% of CRVO cases and within what timeframe? What is it known as and what is it a result of?
Rubeosis
-within 2 to 4 months
The 90 day glaucoma
Result of VEGF release
How should CRVO be referred, ischaemic and non-ischaemic? What is required and especially for what age population?
Refer all new cases, both types
Refer for a medical workup - especially young patients
-determine co-morbidities
List a treatment option to improve VA following CRVO.
There is no proven treatment
List 5 treatment options for CRVO.
Systemic fibrinolysis Retinochoroidal anastamosis Macular grid photocoagulation Decompression of the CRV at the lamina cribrosa Intravitreal triamcinolone
Describe the outcome of macular grid photocoagulation as a treatment option for CRVO.
Improves angio, but no improvement to VA
What is considered to be the best course of action for CRVO?
Anti-VEGF
Discuss what new treatment options can offer for ischaemic CRVO. What is the management (2)?
New treatment offers little
Wait for neovascular changes and begin PRP when it occurs
What is commonly the treatment for non-ischaemic CRVO (2)?
Intravitreal triamcinolone
Anti-VEGF injection
What should all cases of CRVO be followed up for?
Neovascular glaucoma
List 5 predictors of good anti-VEGF responses for non-ischaemic CRVO.
Integrity of the outer retina on OCT Good response to 1st injection Young Better VA at baseline Early intervention
Where do BRVO tend to occur? At what age?
At an AV crossing
Usually >65yoa
List the main risk factor for BRVO. List 4 additonal risk factors.
Hypertension Diabetes Hyperlipidaemia Smoking Renal disease
What should you consider for venous occlusion not occuring at an AV crossing?
Inflammatory disease
-sarcoidosis
What is vision loss like with BRVO? What about with a peripheral occlusion?
Sudden onset visual loss
Peripheral occlusion probably asymptomatic
List four causes of VA loss with BRVO.
Macular oedema
Macular ischaemia
Haemorrhage at the macula
Vitreous haemorrhage 2° to NVE
List 5 signs of BRVO.
Dilated/tortuous veins Haemorrhages (dot/blot/flame) Cotton wool spots Retinal oedema Vitreous haemorrhage
What is hypofluorescence and what does it indicate?
Blockage of background
Capillary non-perfusion
What does hyperfluorescence indicate?
Leakage
List four differential diagnoses for BRVO.
CMV retinitis
Cavernous haemangioma
Periphlebitis (sarcoidosis)
Retinal macroaneurysm
Does the acute phase of untreated BRVO resolve quickly or slowly? Over what timeframe?
Slowly - over 6 to 18 months
What is the prognosis like for untreated BRVO? What is this dependent on (2)?
Reasonable
Dependent on venous drainage and degree of macular ischaemia
Do haemorrhages in BRVO disappear?
Yes, but slowly
What are the chances of spontaneous recovery with BRVO?
20 to 40%
Is it common or rare for patients to improve to 6/12 or better vision after BRVO?
Rare
How should you refer BRVO? Explain the merit in waiting.
Refer, especially in macular involvement
Possibly 3 months allowed for spontaneous recovery
After what timeframe should angiography be performed in BRVO and why?
6 to 12 weeks after haemorrhages have cleared
What is the treatment for macular oedema with BRVO (2)?
Laser photocoagulation
Can also use anti-VEGF injection (recommend to observe for 3 months first and then do after laser)
Is a delay in anti-VEGF injection detrimental for BRVO?
No
List 6 predictors of good anti-VEGF response with BRVO.
VA better than 6/12 Young Retinal haemorrhage Integrity of the outer retina with OCT Good response to first injection Small macular cysts
