Sudden Loss of Vision Flashcards
Things to refer on the same day
- CRAO (less than 4 hrs history)
- ischaemic optic neuropathy
- retinal detachment less than 1 week Hx
- optic neuritis
Things to refer within days
- vein occlusion
- artery occlusion of duration longer than 6 hrs
- sudden deterioration of ARMD
- retinal detachment longer than 1 week
- vitreous haemorrhage
- tumours
- choroiditis, ritinitis
Things to refer to physician, neurologist or stroke unit
- homonymous hemianopia
Characteristics of central retinal artery occlusion
- pale infarcted retina
- non-perfused arteries partly obscured by retinal oedema
- cherry red spot at the macula
- VA is CF or worse
Central retinal artery occlusion may be:
- embolic
- thrombotic
- arteritic (GCA)
Characteristics of central retinal vein occlusion
- dilated tortuous veins
- cotton wool spots
- haemorrhages
- VA 6/18-CF
Causes of vein occlusion
- poorly controlled BP
- diabetes
- hypercoagulable states (incl malignancy)
Complications of vascular occlusion in the eye
- neovasculatisation of the disc, retina and iris
- vitreous haemorrhage
- neovascular glaucoma
Non-schaemic causes of vitreous haemorrhage
- bleeding disorders
- tumours
- retinal detachment
Important cause of ischaemiic optic neuropathy
Giant cell arteritis
Other symptoms of giant cell arteritis
- malaise
- myalgia
- jaw claudication
- weight loss
- scalp tenderness
Treatment of GCA
- prednisone (1mg/kg)
- needs temporal artery biopsy within 10 days
What is an altitudinal field defect?
- either the upper or lower half of visual field is selectively affected
- often creates vertical line across visual field
- often associated with ischamic optic neuropathy
Symptoms of ARMD
- slow loss of vision from scarring round drusen
- sudden loss of vision from bleeding
- metamorphopsia
Symptoms of retinal detachment
- flashing lights
- floaters
- grey curtain from periphery
- loss of vision
Different types of floaters
- muscae volitantes: in posterior vitreous detachment
- showers of dots in vitreous haemorrhage
DD of flashing lights
- scintillating scotomata
- fortification spectrum of migraine
DD of curtain coming down
Amaurosis fugax
Characteristics of choroidal metastasis
- vision usually normal or distorted until a secondary exudative retinal detachment suddenly detaches the macula
Characteristics of choroidal malignant melanoma
- flashing lights or visual loss
- sudden visual loss when fluid exudate or solid tumour detach the fovea
- appears solid elevated lesion with greyish pigmentation
Characteristics of active toxoplasmosis
- old scar surrounded by sheathed vessels and vitreous haze
- poor red reflex
- refer for bactrim, oral steroids and eye monitoring
Signs and symptoms of CRAO
- VA is CF or worse
- afferent puil defect
- pale, infarcted retina
- non-perfused, thread-like arteries, partly obscured by retinal oedema
- cherry red spot at macula
Management of CRAO
- if appropriate, need age-appropriate stroke work-up
- within 4 hrs:
- digital massage of the globe and oral acetazolomide
- get patient to breathe into a paper bag (vasodilation)
Pathogenesis of ischaemic optic neuropathy
- occlusion of the short posterior ciliary artery
Flashing lights
Photopsia
Pathogenesis of optic neuritis
- demyelination
- infective
- immune
- infiltrative
Causes of optic neuritis
- multiple sclerosis
- syphilis
- idiopathic
- HIV
- sarcoidosis
Signs and symptoms of optic neuritis
- loss of vision
- central scotoma
- afferent pupil defect
- loss of colour vision
- optic disc may be swollen
Causes of retinitis and choroiditis
- TB
- syphilis
- CMV
- toxoplasmosis
