Week 2 - D - Ophthamology 3 - Sudden visual loss causes Flashcards
Name some causes of sudden visual loss
Central retinal artery occlusion
Central retinal vein occlusion
Retinal detachment
Vitreous hameorrhage
Transient central retinal artery occlusion
Wet age-related macular degeneratiion
• Pale oedematous retina, thread-like retinal vessels What is this?
Central retinal artery occlusion
What is the main cause of central reitnal artery occlusion? How does the patient present?
Usually carotid artery disease
Paitent presents with profound painless sudden vision loss
Why is there a cherry red spot at the fovea in centra retinal artery occlusion?
The macula is thin and the choroidal blood supply can be seen through the cells of the macula
If the patient presents within 100 minutes with a central retinal artery occlusion, what is the treatment?
Try an ocular massage to move the embolism in the artery from the central to branched retinal artery
Patients rarely recover from CRAO, how is the source of the embolism attempted to be established?
Try using a doppler to identify the location
Doppler is used for arteries and viens
Describe how a patient with a tranisent ischaemic attack would present? What is another name for the transient ischaemic attack of the eye?
Amaurosis fugax
Presents with a sudden painless loss of vision, which is only temporary and is like a curtain coming down over the eye
Immediate referral TIA clinic for amurosis fugax, what drug is given? What can a TIA be a sign of?
Give the patient aspirin
Can be a precursor to stroke
How does apsirin work?
It works by the inhibiting the acitvation COX enzyme (cyclo-oxygenase) which is required for prostoglandin (induces fever) and thromboxane (clotting) synthesis
The major blood supply to the eye are via branches of which artery?
Via branches of the ophthalmic artery which is branch of the internal carotid artery (ICA)
What type of visual defect will this cause? What is this?
This is a branched retinal artery occlusion
Will most likely cause an inferior visual defect as the superior retina has the defect
Describe the findings for central retinal vein occlusion? (fundoscopy findings as well)
Sudden vision loss
On examination has dilated torturous veins and retinal haemorrhages
Also has a swollen optic disc and macular swelling
What is the treatment for central retinal vein occlusion?
treatment would be an anti VEGF (anti vascular endothelial growth factor)
If patients develop complications due to development of new vessels in CRVO, what may be given to prevent vitreous haemorrhage? (can lead to glaucoma)
Patient may be given laser therapy to prevent vitrous haemorrhage but only if neovascularisation is present
What are the usual causes of CRVO? (virchow’s triad)
Hypercoagulability
Stasis of blood
Endothelial damage