Transient monocular vision loss Flashcards
What are the causes of central retinal vein occlusion (CRVO)?
- Atherosclerosis
- Hypertension
- Diabetes mellitus
- Glaucoma
- Polycythaemia
What are the clinical features of non-ischaemic CRVO?
- Subacute, mild to moderate loss of vision in affected eye
- Absent RAPD
What are the ophthalmoscopic findings in non-ischaemic CRVO?
- Few flame-shaped haemorrhages in all 4 retinal quadrants
- Mild/no macular oedema
- Mild/no papilloedema
What are the clinical features of ischaemic CRVO?
- Sudden, severe loss of vision
- RAPD present
What are the ophthalmoscopic findings in ischaemic CRVO?
- Severe haemorrhages in all 4 retinal quadrants and venous thickening
- Cotton wool spots (yellow-white deposits on the retina)
- Severe macular oedema
- Severe papilloedema
How are non-ischaemic and ischaemic CRVO differentiated from one another?
Fluorescein angiography
What are the causes of central retinal artery occlusion (CRAO)?
- Thromboembolism (from atherosclerosis)
- Arteritis (e.g. temporal arteritis)
What are the clinical features of CRAO?
- Sudden , painless loss of vision in affected eye
- Vision loss often described as a descending curtain
- RAPD present
What investigations should be performed when a diagnosis of CRAO is suspected?
- Carotid doppler
- Echo
- Inflammatory markers (ESR/CRP)
- Temporal artery biopsy
What are the ophthalmoscopic findings in CRAO?
- Grey-ish white (cloudy) discolouration of the entire retina
- Cherry-red spot at the fovea centralis
- Retinal plaques/emboli
- Narrowing of all retinal vessels
- Box-carring: segmented appearance of retinal vessels
What is the management for CRAO?
- CRAO is an ophthalmologic emergency*
- Eyeball massage
- Carbogen therapy: inhaling a mixture of 5% CO2 and 95% O2
- Decrease IOP: surgical therapy
What is amaurosis fugax?
Sudden, painless loss of vision that lasts for seconds to minutes and is followed by spontaneous recovery
What is the cause of amaurosis fugax?
Retinal ischaemia following transient occlusion of the central retinal artery by microemboli
What is a potential complication of amaurosis fugax?
TIA
What are the causes of vitreous haemorrhage?
- Proliferative diabetic retinopathy
- Posterior vitreous detachment
- Ocular trauma (particularly in children and young adults)
What are the clinical features of vitreous haemorrhage?
- Sudden, painless visual loss
- Red hue
- New onset of floaters and ‘cobwebs’
- Symptoms which may be worse in the morning if blood settles on the macula
- Hx of diabetes, hypertension, sickle cell, ocular surgery or trauma
- moderate bleed may be described as numerous dark spots
**No photopsia - how to differentiate from PVD and RD
What is the management of vitreous haemorrhage?
Usually observation
- Laser photocoagulation
- Anterior retinal cryotherapy
- Vitrectomy
- Intravitreal anti-VEGF agents
What is posterior vitreous detachment?
Separation of the posterior hyaloid face of the vitreous body from the neurosensory retina
*Most common cause of floaters and flashes
What are the clinical features of posterior vitreous detachment?
- Asymptomatic
- Painless
- Single or multiple floaters; often described as circular, ovoid, or a curvilinear ; often on temporal side of vision
- Photopsia (ocular flash), usually in visual peripheries
- Shower of black specks
What is retinal detachment?
Involves the neurosensory layer of the retina separating off from the underlying retinal pigment epithelium (RPE)
How can retinal detachment be classified?
Rhegmatogenous and non-rhegmatogenous
*Rhegmatogenous is the more common form
What are potential risk factors for retinal detachment?
Myopia
FHx of retinal break or detachment
Previous history of retinal break or detachment
What are the clinical features of retinal detachment?
- New onset of floaters and flashes
- Sudden, painless, usually progressive visual field loss
- Vision loss may be described as a dark curtain/shadow, which usually starts in the periphery and then progresses towards the centre
- RAPD will be present if the macula is detached (or if 2+ quadrants of the non-macular retina have detached)
