Retinal Vascular Diseases Flashcards
what are the 4 common categories of diabetes?
- Type 1 – Insulin deficiency
- Type 2 – Insulin resistance
- Gestational diabetes
- Specific types (monogenic diabetes syndrome etc.)
name 3 of the most common complications of diabetes?
- Diabetic Retinopathy & Diabetic Maculopathy
- Refractive
- Iridopathy
what are the less common complications of diabetes?
- (early onset) Senile Cataract (age related)
- Styes, Blepharitis & Xanthelasmata
- Recurrent subconjunctival haemorrhages
- Ocular motor palsies
- Corneal ulcers and sensitivity
- Rubeosis Iridis (Neovascular glaucoma)
what is primary hypertension?
high blood pressure that does not have a known cause
name 6 risk factors of diabetic retinopathy
Diabetes duration
Poor control of diabetes
Pregnancy
Hypertension
Nephropathy (kidney disease)
Obesity
What is the pathogenesis of diabetic retinopathy?
- hyperglycaemia causes increased blood viscosity
- this causes damages to retinal pericytes (this usually goes undetected)
- when the pericytes are damaged, capillary walls in microvasculature of the retina weaken leading them to close as microaneurysms
- chronic leakage from the vasculature results in oedema and exudates which can be seen as white flecks on the retina (this may or may not be symptomatic
- proliferative diabetic retinopathy is where there is retinal ischaemia which stimulates production of growth factors such as VEGF, IGF-1
- this causes neovascularisation which could lead to vitreous haemorrhages and retinal detachment
How do you manage diabetic retinopathy at each of the stages?
-background: inform GP
-pre proliferative: inform GP
-proliferative: urgent referral to HES
What are the signs associated with background diabetic retinopathy?
-microaneurysms
-dot and blot haemorrhages
-flame haemorrhages
-hard exudates
What are the signs associated with pre proliferative diabetic retinopathy
-cotton wool spots
-venous irregularities
-intraretinal microvascular abnormalities (IRMA) (this is where there is abnormal branching or dilation of existing vessels)
-dark blot haemorrhages
What are the signs associated with proliferative diabetic retinopathy
- Neovascularisation at the Disc (NVD)
- Neovascularisation Elsewhere (NVE)
- Pre-retinal & Vitreous haemorrhages
- Tractional retinal detachment
What are the signs associated with diabetic maculopathies?
Exudative, focal/diffuse, cystoid/diffuse oedema, Ischaemia
when is macular oedema clinically significant?
-Retinal oedema within 500um of the centre of the fovea
-Hard exudates within 500um
of centre of fovea, if associated
with retinal thickening (can be
outside 500um area
-Retinal oedema 1 disc area or larger, any part of which is within 1DD (1500um) of the
centre of fovea
what complications can diabetic retinopathy cause?
-earlier onset of age-related cataract
-extraocular muscle palsies
-iris complications
-Lids and lash complications like blepharitis, styes and infections and xanthelasma
-corneal complications
What iris complications can diabetic retinopathy cause?
- Iris transillumination
- Rubeosis iridis
- Pupil size - small irregular - sympathetic denervation
- Increased IOP due to leakage of cells from new blood vessels
what corneal complications can diabetic retinopathy cause?
Recurrent epithelial erosions
Transient punctate keratitis
Stromal oedema
Reduced corneal sensitivity
Reduced healing rate
Increased fragility
Reduced resistance to infection
what ocular signs in the retina are caused by hypertension?
- Hypertensive Retinopathy
- Choroidopathy
- Disc oedema
what are the 2 types of hypertension?
-Primary hypertension (no distinct cause)
-Secondary which can be caused by renal disease or endocrine disease, rarely congenital coarctation (narrowing) of the aorta
what ocular complications arise as a result of hypertension
- AION (non-arteritic– often reduced VA and swollen disc)
- Retinal arteriole and vein occlusions
- Retinal macro-aneurysms (and retinal emboli)
- Ocular motor nerve palsy
- Glaucomatous optic neuropathy
give the pathogenesis of hypertensive retinopathy
- VASOCONSTRICTIVE PHASE autoregulation mechanism results in vaso-constriction visible as generalised arteriole narrowing
- SCLEROTIC PHASE - persistent high blood pressure causes both arterial sclerosis = wall narrowing and atherosclerosis which leads to the lumen to narrow. associated with changes in arterial light reflex and A/V crossing
3.EXUDATIVE PHASE blood retinal barrier disrupted due to loss of smooth muscles and
endothelial cells. - COMPLICATIONS OF SCLERIOTIC PHASE - macroaneurysms, microaneurysms, CRA & CRV
occlusions, epiretinal membrane formation
what are the different signs of arteriovenous nipping?
-Gunn’s sign
-Salus’s sign
-Bonnet sign
see more in screenshots folder
what retinal grading system would you use for hypertensive retinopathy?
Keith–Wagener–Barker Classification System:
Grade 1 -Mild narrowing of the retinal artery.
Grade 2 -Severe or tighter constrictions of the retinal
artery. This is called arteriovenous, or AV, nipping.
Grade 3 - As above plus retinal oedema, microaneurysms, cotton-wool spots and retinal haemorrhages.
Grade 4 –As above plus optic disc swelling (papilledema) and macular oedema, associated with a higher risk of stroke,
kidney or heart disease.
what retinal grading system would you use for Arteriosclerotic Retinopathy - Arteriolar sclerosis
Scheie Classification System
Grade 1 –Broadening of arteriole light reflex /
narrowing
Grade 2 –As above + deflection of vein at A/V
crossing (Salus’ sign)
Grade 3 - As above + copper wiring of arterioles,
banking of vein (Bonnets sign), tapering of vein
(Gunn’s sign)
Grade 4 –As above + silver wiring
what are the signs of the exudative phase of hypertensive retinopathy?
-Haemorrhages, Oedema and Cotton Wool Spots (CWS)
-Maybe associated with disc swelling which usually indicates severe HBP/malignant
hypertension.
what are the main retinal signs of hypertensive retinopathy?
- Retinal oedema
- Hard exudates (lipid deposits)
- Cotton wool spots
- Retinal haemorrhages
- FIPTs (focal intraretinal periarteriole transudates) ,round/oval white lesions <1/4 DD size, plasma macromolecules along deep retinal arterioles, Specific to hypertension
- IRMA (due to capillary occlusion
what are the two theories for the cause of disk oedema and malignant hypertension?
- raised intracranial pressure
(papilloedema) - disc ischaemia
what is a sign that the retinopathy is caused by hypertension rather than diabetes?
macroaneurysms
for hypertensive choroidopathy, who does it occur in? what is it associated with? what are its clinical signs? what could it develop into?
-Occurs in severe hypertension - often in relatively young individuals
-Often associated with renal disease, toxaemia of pregnancy or collagen vascular diseases.
-clinical signs are RPE lesions called Elschnig’s spots and Siegrists streaks
-May develop serous detachments of neurosensory retina
which retinopathy sign has the highest association of stroke risk?
cotton wool spots and 2nd is microaneurysms
What is the most severe sign of hypertensive retinopathy?
swelling of the optic disk
for the severities of mild, moderate and severe/malignant hypertensive retinopathies, what is the referral guide?
- Mild
(Routine referral to GP if undiagnosed)
-Moderate
(Referral to GP / consider HES if diabetic, visual symptoms or vascular complications) - Severe / Malignant
(Same day referral to HES / Emergency to A&E if BP
>180/120)
what are the most common causes of retinal vein and retinal artery occlusion?
-atherosclerotic vessels
-high intra-cranial pressure
what diseases can cause retinal vein and retinal artery occlusion?
those that cause increased blood viscosity:
* Diabetes
* Vasculitis
* Phrombophilicdisorders
how does Central retinal vein occlusion - CRVO occur?
thrombosis of the central
retinal vein at the lamina cribosa or retro-laminar
how does branch retinal vein occlusion (BRVO) occur?
Occlusion typically at AV crossing. its 7x more common than CRVO
how does hemi-retinal vein occlusion occur?
by occlusion at the optic disk
what might tell you a retinal vein/ artery occlusion is ischaemic?
*The findings are more pronounced in ischaemic occlusions
* VA commonly less than 6/60
* RAPD present
* Severe disc / macula oedema
* Neovascular changes –disc (NVD) retina (NVE)
or iris (NVI)
what are the differential diagnosis of retinal vein occlusions?
- Ocular ischaemic syndrome
- Asymmetrical diabetic retinopathy
- Hypertensive retinopathy
- Macroaneurysm
- Peripheral choroidal neovascularisation
what investigations should you do if you think someone has a retinal vein occlusion?
- best corrected visual acuity
- colour fundus photography
- gonioscopy (if available and if ischaemic CRVO is
suspected) - optical coherence tomography (OCT) (if available)
- IOP check
what are the signs of central retinal vein occlusion?
-blot and flame haemorrhages
-dilated and tortuous veins
-optic disk oedema
-cotton wool spots
-all four quadrants are involved
what are the signs of branch retinal vein occlusion?
-disk swelling (uncommon)
-cws and localised oedema (possible)
-haemorrhages along one arcade only
what are the signs of hemi-retinal vein occlusion?
-haemorrhages in one half of the fundus
-may have disk swelling
how is the outer retina supplied with blood?
via ciliary arteries and choriocapillaris
how is inner retina supplied with blood
via central retinal artery
what is the pathogenesis of artery occlusion?
-emboli where usually atherosclerotic plaque causes blockage
-vasospasm where contraction of the arterial wall causes interruption of blood supply
what is rubeosis iridis? (neovascular iris NVI)
- Ischaemia in the eye
- Starts at the iris margin
- May cause intractable Neovascular glaucoma
- ‘100-day glaucoma’ following
ischaemic central retinal vein
occlusion
what can thrombosis be due to?
- Diabetes
- High blood pressure
- Clotting disorders
what can atherosclerosis be due to?
- High cholesterol
- High blood pressure
- Diabetes
what are the risk factors for retinal artery occlusion?
-inflammation
-atherosclerosis
-vasospasm
-thrombophilic disorders
for inflammation,
-how does it increase risk for arterial vein occlusion?
-what kind of conditions is it linked to?
by increasing blood viscosity
linked to
* Sickle cell
* SUSAC syndrome
* Polyangitis
*giant cell arteritis MOST COMMON
as a risk factor for retinal artery occlusion, where is atherosclerosis commonly found what part of vessels is it most commonly found in?
-Commonly found in the carotid arteries
-Most common in the bifurcations of vessels
what are the 4 types of retinal artery occlusion?
-Central retinal artery occlusion (CRAO)
-Branch retinal artery occlusion (BRAO)
-cilioretinal artery occlusion
-amarosis fugax
what are the signs and symptoms of CRAO?
- Sudden and complete painless loss of vision
- Pale and oedematous retina ‘whitening’
- Cherry red spot & Very attenuated blood vessels
- Dense RAPD
what are the signs and symptoms of BRAO
- Scotoma
- Visual acuity dependent on location
- May be asymptomatic
- RAPD Mild or absent
what are the signs and symptoms of amarosis fugax?
- Examination normal
- Very specific history
- Curtain coming over vision to blackness
- Recovery is similar
- Frequent occurrence indicates very high
risk of stroke - Falls under transient ischemic attack
What are the treatments for diabetic retinopathy?
- Focal/Grid Laser or Pan-retinal photocoagulation (Pre
or proliferative retinopathy) - Corticosteroids (oedema)
- Anti-VEGF (neovascularisation)
- Pars plana vitrectomy (traction or vitreous
haemorrhage)
how do you treat tractional retinal detachment?
via vitrectomy
why is the rnfl thinner in diabetes patients?
because loss of retinal ganglion cells in diabetes means diabetic retinopathy causes abnormal retinal function due to thinning of the axon (panretinal photocoagulation)
how can you systemically control diabetic retinopathy?
- Glycaemic control -HbA1c <7% (53mmol/mol)
- Hypertension control -BP <130mmHg
- Lowering blood lipids
how can you treat neovascularisation of the iris?
- PRP (pan retinal photocoagulation)
- Intravitreal injections of anti VEGF
what can anti VEGF injections be used to treat? why should you be careful when using them in long term?
- Neovascularisation
-due to link with atrophy of photoreceptors/Muller cells.
how do you carry out diabetic eye screening in wales? what is is called?
Diabetic retinopathy screening service for Wales (DRSSW)
1. All people aged 12 and over with a diagnosis of diabetes and
who are registered with a GP in Wales should undergo diabetic eye screening, if not inform GP
2. Annual (or bi-annual if low risk) Stereo-photography with
dilation.
3. Visual Acuity recorded.
4. Automatic referral to Ophthalmology or Community
Optometrists.
what lifestyle changes can you recommend to prevent hypertension?
- Weight loss
- Reduce dietary sodium intake
- Balanced diet
- Exercise -regular aerobic physical activity
- Limit alcohol consumption
name a classification system for hypertensive retinopathy
Wong and Mitchell classification system
What are the management guidelines for retinal vein occlusion?
“Urgent referral to an ophthalmologist (the time to referral should not exceed 2–4 weeks from
presentation) PLUS Urgent referral to GP for medical management and investigation” - college of optometrists
what systemic investigations can you do if you suspect a patient has retinal vein occlusion?
- make sure there is no increase in risk of stroke in patients with RVO
- Medical history
- Blood pressure
- Blood glucose
- Bloods –full blood count and ESR (marker of inflammation)
what conditions can retinal vein occlusion be associated with in younger patients (<50)
- Hypertension
- Dyslipidaemia
- Diabetes
- Possible role for
dehydration
what ophthalmic investigations can you do if you suspect retinal vein occlusion?
- OCT
- OCTA
- Fundus photography
- Fluorescein angiography (less
common now)
what are the ophthalmology treatments for
-macula oedema
-neovascular changes
in someone with retinal vein occlusion?
-anti-VEGF and corticosteroids
-PRP
what do anti-VEGF injections do?
they prevent leakage by reducing permeability of vessels
what do corticosteroids do?
act as an anti-inflammatory but have side effects of cataracts and increased IOP
when is there risk of neovascular changes in the retina?
-in ischemic RVO
-when capillary non-perfusion of >10 disc areas at the posterior pole of eyes with CRVO suggests high risk of neovascularisation
-when widefield imaging has shown that there are larger areas of peripheral
non-perfusion, >75 disc areas, associated with risk of neovasc
what types of VO have better prognosis?
brvo has better prognosis than crvo
when should treatment for rvo be discontinued?
if there is no response after 6 treatments
what does prognosis of rvo depend on?
levels of ischaemia
what are the main causes of vision loss in RVO?
Macular oedema or ischaemia
give some acute treatments of retinal artery occlusion
- Supine position
- Ocular massage
- Anterior chamber paracentesis
- Medical reduction of IOP
- Rebreathing into a paper bag
- Hyperosmotic agents
- YAG laser
- Thrombolysis
give the systemic managements of retinal artery oclusion
- Referral to stroke team from Ophthalmology
- Addressing general cardiovascular risk factors
- Anti-platelet therapy
- Carotid endarterectomy where appropriate
what is the prognosis for retinal artery oclusion?
- Acute onset -Emergency referral
- Recovery of vision has a low probability
- Nerve fibre loss can be irreversible within as little as 2-4 hours
- BRAO may have apparent improvement as adaptation to the scotoma occurs
what type of retinal artery occlusion is an emergency?
central retinal artery occlusion
