Vascular Occlusions Flashcards
Do vascular occlusions tend to be bilateral or unilateral?
Unilateral
(Very rarely bilateral)
In what patient may a vascualr occlusion go unnoticed?
In elderly patients
What symptoms do vascular occlusions cause?
They tend to cause a sudden painless loss of vision.
Are vascular occlusions exclusive to the elderly?
Vascular occlusions are not exclusive to the elderly although they typically affect the elderly.
What is central retinal artery occlusion?
- Obstruction of central retinal artery by embolus or thrombus
- Usually below surface of optic nerve head
What is the epidemiology of central retinal artery occlusion?
- Onset mid-sixties
- Male to female ratio 2:1
- Rare (incidence 1.9 in 100,000 in U.S.)
How does a patient with Central Retinal Artery Occlusion present?
They present with a sudden painless profound (this means severe) loss of vision
This may be preceded by a transient loss of vision ( i.e. transient loss of vsion comes before profound loss of vision)
(Amaurosis Fugax)
What is Amaurosis fugax?
Transient (this means to last only for a short period of time) obscuration of retinal artery by embolus. –> This is also known as a Transient ischaemic attack (TIA).
Causes transient loss of vision.
What symptoms does Amaurosis Fugax have?
ØSudden monocular loss of vision
ØPainless
Ø“Like a blind coming down”
ØClears slowly in reverse direction (i.e. as if the blind is coming up)
ØRepetitive ( happens a few times in a period of say 24 hours)
What is the optometric managment for Amaurosis fugax?
ØRefer to G.P. urgently after excluding giant cell arteritis
What are the early signs of central retinal artery occlusion?
•Visual acuity is severly reduced to usually Counting Figures to just about Light Perecption
- Exceptions to this are those with a cilio-retinal artery ( which makes up 25% of the population)
Signs at the back of the eye include:
- A Pale oedematous retina especially at the posterior pole
- Cherry red spot at macula
- Arterial attenuation – thinner/weakened arteries
- Segmentation – changes at the arteries
- Emboli may be seen
- RAPD ( thus important to do the swinging lights test)
Why is a cherry red spot at the macuola seen in central retinal artery occlusion?
The appearance of a cherry red spot , is due to Macula blood supply coming from the choroid via posterior ciliary arteries ( i.e. coming from a different artery - one that hasnt been occluded) and therefore the surrounding retina seems pale in comparison, giving the appearance of a deep red spot.
(Macula is generally thinner so you see this redness coming through)
What is RAPD?
How do we test for RAPD and what do we see if RAPD is present in the test?
Relative Afferent Pupillary Defect - Relative Afferent Pupillary Defect (RAPD) is a condition in which pupils respond differently to light stimuli shone in one eye at a time due to unilateral or asymmetrical disease of the retina or optic nerve.
We test for it using the swinging lights test.
What are the late signs of central retinal artery occlusion?
- Optic disc atrophy ( so pale)
- Continued Arterial attenuation and segmentation
- VA usually remains markedly reduced despite treatment
What is stenosis?
A stenosis is an abnormal narrowing in a blood vessel or other tubular organ or structure
What is a bifurcation?
The division of something into two branches or parts
i.e. if an embolus was lodged in the bifrucation - it would be lodged at the point at which the vessel branches out.
What are the two causes of Central Retinal Artery Occlusion and which one is more common?
The two causes of Central Retinal Artery Occlusion are an embolus or thrombus.
Embolus > Thrombus
The embolus is as a result of carotid artery heart disease.
The thrombus can be a result of either a blood clot or stenosis of the carotid artery.
What are the different ways in which an embolus may arise?
- Cholesterol crystals from carotid arteries may break off and travel through the vascular system causing a blockage
- The embolus may be from Platelet-fibrin arising from large vessel stenosis
- Calcific emboli arising from carotid valve stenosis
What are the arrows pointing to in the pictures.
What technique has been used to produce the image on the right?
The arrow in the coloured photo is pointing to an embolus.
The black and white photo has been produced via fluorescein angiography .
The arrow on the black and white photo is showing the appearance of a darkened vessel - i.e. a vessel in which blood is not flowing through.
What are the risk factors for Central Retinal Artery Occlusion?
- Systemic hypertension
- Diabetes mellitus
- Hyper-lipidemia
- Carotid artery disease
- Coronary artery disease
- TIA (Transient Ischaemic attack)/CVA
- Giant cell arteritis
- Tobacco smoking
What is the optometric managment of Central Retinal Artery Occlusion?
•Measure visual acuity
-Check pupils
•Urgent referral to Eye Casualty
-If < 12 hours old ( there is a chance we can restore vision the less time it has been)
•First Aid - aim to dislodge embolus - we do this by the following:
- Ocular digital massage
- Breathe into paper bag to Increase CO2 levels - to essentially dislodge the embolus
What is the Ophthalmological management for Central Retinal Artery Occlusion?
• To Reduce IOP - this is done via the following:
- Anterior chamber paracentesis
- Intravenous acetazolamide and ocular massage
•Dilation of arteries - this may be done via the following:
- Ocular massage
- Retrobulbar vasodilator drugs
- Inhalation of carbogen
•Lysing of embolus/thrombus
•Systemic anticoagulants
•INVESTIGATION OF CAUSE
-Increased mortality ( state of being subject to death) with presence of emboli
In what age group is BRANCH retinal artery occlusion most common?
70+ pxs
What is normally the cause of BRANCH Retinal Artery Occlusion?
An embolus
What is the most common location for a BRANCH Retinal Artery Occlusion?
90% of cases are occlusion of temporal retinal arteries
What are the symptoms of BRANCH Retinal Artery Occlusion?
•Sudden painless loss of vision
- Hemifield or sector loss of vision
- Likely superior Visual Field loss
What is the prognosis of a Branch Retinal Artery like?
After course of treatment around 74% of px have a visual acuity around 6/12 however the visual field defect will still be there.
What is a central retinal vein occlusion?
An Obstruction of the central retinal vein below the lamina cribosa
What is the epidemiology of Central Retinal Vein Occlusion?
- More commonly affects older people in their mid-sixties, but can also occur in younger patients
- Male to female ratio equal 5.2 in 1,000 ( so slight prefernce for males)
What are the symptoms of Central Retinal Vein Occlusion?
- Sudden painless loss of vision
- Variable deficit (i.e. visual acuity affected is variable)
- May go unnoticed (as it only affects one eye and to a variable degree)
What are the signs of central retinal vein occlusion?
- Blood and thunder” is the term given as there is a lot of activity in all four quadrants.
- Flame-shaped haemorrhages in all 4 quadrants
- Disc oedema
- Venous dilation
- Multiple cotton wool spots
- Px is likely to have RAPD
[Macula oedema may occur)
What are the two types of Central Retinal vein Occlusion?
Ischaemic and Non-Ischaemic.
If untreated what percentage of Non-Ischaemic Central Retinal Vein Occlusions become Ischaemic?
20%
What are the differences in signs between Ischaemic and Non-Ischaemic Central Retinal Vein Occlusions?
What is the difference in fundus photography between an Ischaemic and Non-Ischaemic Central retinal Vein Occlusion?
What is a possible complication of Ischaemic Central Retinal Vein Occlusion?
That it develops to form retinal and iris neovascularisation.
Which can cause neovascular glaucoma.
What is neovascular glaucoma also called and why?
“100 day glaucoma” because it typically presents around 3 months after central retinal vein occlusion
What is neovascular glaucoma caused by?
Retinal hypoxia which causes angiogensis substances to be released which induce formation of new vessels in the angle. Thus the Fibrovascular membrane develops across the trabecular meshwork.
Why is neovascular glaucoma concerning?
Early intervention is required and even then the efefcts can be quite devistating.
‘Intractable’ - i.e. this condition is hard to deal with
What are the two main types of causes of Central Retinal Vein Occlusion? - give examples of each
Systemic and ocular.
Systemic causes include:
- Systemic hypertension
- Diabetes
- Arteriosclerosis
- Hyperviscosity syndromes
- Oral contraceptive pill is a risk factor
Ocular causes include:
•Raised IOP > 30mmHG
What is the optometric managment of Central Retinal Vein Occlusion?
First thing to do is check the intra-ocular pressure depending on that you…
What is the ophthalmological managment for Central Retinal vein occlusion?
•Fluorescein angiogram will occur to check whether it is Ischaemic or non-ischaemic.
•New vessels will be dealth with via:
- Pan-retinal photocoagulation
- or Intra-vitreal anti-VEGF? ( depends case by case)
•If there is the presence of Macula oedema:
- Intravitreal steroids will be used e.g. triamcinolone acetonide, or dexamethasone bigradeable implant
- Intravitreal anti-VEGF (eg Lucentis)
•Investigation and treatment of underlying cause will be done
What is the cause of a Branch retinal vein occlusion?
Normally a systemic cardiovascular cause
What is the symptom of a branch retinal vein occulsion?
Hemi-field loss
What clinical signs will a px with a branch retinal vein occlusion present with?
- An Obstructed vein which is dilated and tortuous
- Retinal oedema
- Scattered superficial and deep retinal haemorrhages- that respect the horizontal midline, and are confined to one quadrant
What is the optometric management of Branch Retinal Vein Occlusion?
- Measure visual acuity
- Fundus examination (Dilated BIO)
- Check Pupil reactions
- Check Visual field
•
- Refer to GP cardiovascular investigation
- Ophthalmological referral
What is the ophthalmological management of Branch retinal vein occlusion?
- Fluorescein angiogram
- Grid laser coagulation if macula oedema persistent
- Retinal neovascularisation rarer in BRVO
- Prognosis good if treated VA ≥6/12
ØBut 25% will have VA <6/60
Which image shows a central retinal vein occlusion and which image shows a branch retinal vein occlusion?
The branch retinal vein occlusion is where the haemorrhaging is restricted to one quadrant.
What is anterior Ischaemic Optic Neuropathy?
Ischaemia of the anterior optic nerve head by occlusion of the posterior ciliary arteries.
What is the epidemiology of Anterior Ischaemic Optic Neuropathy?
- Almost exclusively after the age of 50 years
- Incidence 18 per 100,000 after 50 years
- Woman > men (2:1 ratio)
What are the two types of anterior Ischaemic optic neuropathy?
Arteritic (A-AION)
and
Non-Arteritic (NA-AION)
Which type of Anterior Ischaemic Optic Neuropathy is most common?
Non-Arteritic Anterior Optic Neuropathy (NA-AION)
It accounts for about 90-95% of cases
What is Arteritic Anterior Ischaemic Optic Neuropathy (A-AION) associated with?
(Temporal) Artertitis
What are the symptoms of Arteritic Anterior Ischaemic Optic Neuropathy (A-AION)?
Profound Loss of vision ( to the point where the px has either no light perception , light perception, or can just about see hand movements).
What is the typical age group for Arteritic Anterior Ischaemic Optic neuropathy (A-AION)?
70-80 age group (i.e. Older Pxs)
What are the clinical signs of Arteritic Anterior Ischaemic Optic Neuropathy?
- Pale oedematous optic nerve head
- There may be Splinter haemorrhages on the optic disc
- RAPD
What are the complications/risks of Arteritic Anterior Ischaemic Optic Neuropathy (A-AION)?
- Risk of visual loss in other eye
- Myocardial infarction
- Renal failure
- Aortic aneurysm
What is temporal arteritis and what is it also known as?
It is the inflammation of medium and large arteries.
It is also known as Giant cell arteritis (GCA)
What are the symptoms of Temporal/Giant cell arteritis?
•Headache which is:
- normally constant
- has a gradual onset to a diffuse severe aching
- superficial scalp tenderness - temporally
- worse at night and in the cold
•General malaise, weight loss, jaw claudication, amaurosis fugax
•
•Polymyalgia rheumatica
What is malaise?
A general feeling of discomfort, illness, or unease whose exact cause is difficult to identify.
What is jaw claudication?
Pain in the jaw associated with chewing
What are the symptoms of Non-Arteritic Anterior Ischaemic Optic neuropathy ?
•Sudden loss of vision
ØMild to severe
ØUsually on waking
ØVision loss either static or progressive
What is Non-Arteritic Anterior Ischameic Optic Neuropathy associated with?
Hypertension and diabetes
What are the clinical signs of Non-Arteritic Anterior Ischaemic Optic Neuropathy?
•Oedematous optic nerve head
ØDiffuse or segmental
ØHyperaemic or pale
i.e. shows an ‘at risk’ disc
•Visual field loss
ØUsually altitudinal
•Contralateral eye ( i.e. eye not affected) shows:
ØSmall disc
ØSmall or absent cup
True or false - 20% of Pxs with Non-Arteritic Anterior Optic Neuropathy lose vision in the other eye within 5 years.
True
What’s the prognosis like for Non-Arteritic Anterior Ischaemic Optic Neuropathy?
Only a third of Pxs are left with near normal vision after treatment.
What is the optometric management for Anterior Ischaemic Optic Neuropathy?
To investigate:
- VA, Pupils, Colour vision, VFs, IOP
- Dilated fundus examination?
EMERGENCY REFERRAL TO CASUALTY - contact ophthalmologist
[Assume arteritic until proven wrong]
What is the ophthalmological management for Anterior Ischaemic Optic Neuropathy?
Investigation:
- Blood Tests
- Temporal Artery Biopsy
- Scans (Doppler, MRI)
Management:
- Aspirin, treatment of cardiovascular problem
- If arteritic high doses of systemic steroids for years
