Sudden (painless) Loss of Vision Flashcards
What is sudden painless loss of vision?
Acute, painless reduction or loss of vision in one or both eyes, often due to retinal or vascular causes.
What are common causes of sudden painless loss of vision?
Central retinal artery occlusion, central retinal vein occlusion, retinal detachment, vitreous haemorrhage, and optic neuropathy.
What is central retinal artery occlusion (CRAO)?
Blockage of the central retinal artery, causing ischaemia of the retina and sudden vision loss.
What is central retinal vein occlusion (CRVO)?
Blockage of the central retinal vein, leading to retinal haemorrhages and oedema.
What are the symptoms of CRAO?
Sudden, profound vision loss in one eye, often described as “like a curtain coming down.”
What are the symptoms of CRVO?
Painless loss of vision that can range from mild to severe, often with blurred or hazy vision.
What is retinal detachment?
Separation of the neurosensory retina from the underlying pigment epithelium, causing vision loss.
What is vitreous haemorrhage?
Bleeding into the vitreous cavity, often causing sudden vision loss or dark spots in vision.
What are the risk factors for CRAO?
Atherosclerosis, carotid artery disease, atrial fibrillation, and hypertension.
What are the risk factors for CRVO?
Hypertension, diabetes, glaucoma, and hypercoagulable states.
What is the “cherry-red spot” in CRAO?
A characteristic fundoscopic finding caused by retinal ischaemia and preserved choroidal circulation.
What are the fundoscopic findings in CRVO?
Retinal haemorrhages, optic disc oedema, and “blood and thunder” appearance.
What is amaurosis fugax?
Transient monocular vision loss caused by temporary retinal ischaemia, often described as a “shade” over vision.
What is optic neuropathy?
Damage to the optic nerve, commonly due to ischaemia or inflammation, causing sudden vision loss.
What investigations are needed for CRAO?
Fundoscopy, carotid Doppler ultrasound, ECG, and blood tests for vascular risk factors.
What investigations are needed for CRVO?
Fundoscopy, optical coherence tomography (OCT), and blood tests for hypercoagulable states.
What is the immediate management of CRAO?
Ocular massage, reducing intraocular pressure, and referral to a stroke unit for systemic management.
What is the treatment for CRVO?
Intravitreal anti-VEGF therapy or corticosteroids to reduce macular oedema and prevent complications.
What are the complications of untreated CRVO?
Neovascular glaucoma, persistent macular oedema, and permanent vision loss.
What is the role of fluorescein angiography in sudden vision loss?
It helps identify retinal vessel blockages and assess retinal perfusion.
What is the prognosis for CRAO?
Poor, with most patients experiencing permanent severe vision loss despite treatment.
What is the prognosis for CRVO?
Variable; early treatment improves outcomes, but some patients develop complications affecting vision.
What systemic conditions can cause sudden painless vision loss?
Giant cell arteritis, systemic embolism, or hypercoagulable disorders.
Why is urgent referral important in sudden painless vision loss?
Early intervention can prevent further vision loss and address systemic causes like stroke.
