CRVO Flashcards
What is CRVO? and how does it occur?
CRVO = the occlusion of the central retinal veins at the level of the lamiina cribosa or just behind.
Cause = Thrombosis (blood clot)
What is the pathogenesis of CRVO?
A
1. Occlusion of the central retinal vein - therefore oxygenated blood can’t get to the eye = hypoxia
- Hypoxia causes blood vessels to get damaged.
- This causes leakage = haemorrhages and oedema.
- Leukocytes cause capillary occlusion = no oxygen transfer to cells, leading to retinal ischaemia.
what causes a thrombus?
Physical changes
* Arteriosclerosis of neighbouring artery
-shares common advantages sheath. artery on top of vein hardens. and compresses it we get a back log of blood. that becomes a clot . then get thrombus formed.
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* Vessel wall changes e.g. phlebitis
-thrombosis due to physical changes in the wall making ut hard for the blood to go through
-inflammation. of vein , vein becomes thicker and swollen = get blood clot .
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* Raised IOP (>30mmHg)
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Blood abnormality
* High blood viscosity
* Coagulation disorders
when someone has blood disease blood itself is wquite thick so cold easily form clots and that can form a thrombus..
What are the risk factors of CRVO?
- Age 50+ (90%)
- Hypertension
- Hyper-lipidaemia
- Diabetes
- Smoking
- Raised IOP (>30mmHg)
- Oral contraceptive pill (if predisposed)
- Thrombophilia
- Systemic inflammatory disease e.g. Sarcoidosis, Behcet’s disease
- Hypothyroidism
- Chronic renal failure
OAG
CVD
Tortuous dilated retinal veins in all 4 quadrants
* Round/blot and flame haemorrhages
* CWS?
* Possible macula oedema
* Possible disc oedema
cheese tomato pizza appearance
What are the two types of CRVO?
- Non-Ischaemic (75% of cases, concern = turning into ischaemic CRVO.
- Ischaemic (more serve, concern = could develop neovascularisation)
What are the 3 symptoms for Non-Ischaemic CRVO?
1.Sudden onset,
2.unilateral,
3. blurred vision (6/36-6/60)
What are the 3 symptoms for Ischaemic CRVO?
- Sudden,
- unilateral,
3.severe visual loss (<6/60-CF)
Occasionally presentation may be with pain, redness and photophobia due to neovascular glaucom
What are the 7 signs of Non-Ischaemic CRVO?
- Tortuous dilated retinal veins in all 4 quadrants.
- Round/Blot/Flame Haemorrhages
- Occasional CWS
- Mild/Mod Macula Oedema
- Mild/Mod Disc Oedema
- Mild/Absent RAPD
- Acute signs resolve over 6-12 months
What are 7 main signs of Ischaemic CRVO?
- Tortuous and engorgement of retinal veins in all 4 quadrants.
- Extensive deep haemorrhages
- Multiple CWS
- Extensive Oedema
- Optic Disc Oedema
- Marked RAPD
- Acute signs resolve over 9-12 months
What is the prognosis/concern of non ischemic CRVO?
Main concern: possibility of conversion to ischaemic
Approx 50% will return to normal/near normal VA
What is the prognosis/concern of ischemic crvo?
Main concern: development of neovascularisation
What are the 3 referral options for CRVO?
- If IOP normal + non-ischaemic = ROUTINE <13 weeks-
Refer to ophthalmology - Refer to GP- for cardiovascular work up
- If elevetated IOP (up to 40mmHg) + Ischaemic = URGENT ( within 1 week)
- Refer to ophthalmology
- Refer to GP
- If IOP > 40mmHg + Ischaemic = EMERGENCY
If you are unsure whether it is ischaemic: URGENT referral
What is the management of CRVO?
opthalmology:
- OCT- A + FFA
- For non ischaemic - follow up every 3-6 months every 2-3 yrs.
- For ischaemic - follow up monthly for 6 months.
(If macula Oedema present -> Intravitreal
Anti VEGF agents),Intra-vitrealsteroids
(If neovascularisation -> Laser pan-retinal photocoagulation) (LASER PRP)
If FFA shows 10DD of capillary non prefusion = ischaemic
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GP
GP = manage BP, cholesterol, thyroid function + any other systemic disease
» Identify underlying cause
» Identify any underlying systemic disease
» Treat underlying disease and address risk factors
