Neuropthalmology Flashcards
What does PITS stand for?
Parietal lobe- Inferior visual field
Temporal lobe- Superior visual field
What causes bilateral hemianopia & what is it?
Pituitary tumours press on optic chiasm
Missing inner or outer half of visual field in both eyes.
What causes right homonymous hemianopia?
Lesion on the LEFT optic tract
Right visual field of both eyes blind
What causes right superior quadrantopia?
Lesions in Meyer’s loop in Temporal lobe
What causes Right Inferior quadrantopia?
Parietal lobe lesions
What causes right homonymous hemianopia with macular sparing?
Lesion in striate/visual cortex
What causes vision loss in one eye & what symptoms associated?
Optic nerve lesion or neuritis Eye pain on movement Decreased acuity Decreased colour Afferent pupilliary defect
What causes a blind spot?
Lesion at nerve head
Causes of Papilloedema
Increased ICP: Hypertension Addisons Hypoparathryroidism Hypercapnia Right sided heart failure Pulmonary Hypertension Renal Failure
What is papilloedema?
Raised ICP causes intra neuronal ischaemic damage affecting peripheral vision the most
Also swelling of optic disc (bilateral for several seconds)
If chronic causes optic atrophy and visual failure.
3rd Nerve Palsy looks like..?
Down and Out Eye
Trochlear nerve palsy looks like..?
Head tilt
Abducens Nerve Palsy looks like…?
Eye pulled in
What diseases cause nystagmus?
MS, Wernicke’s, Stroke
Causes of transient visual loss
Amaurosis fugax
Migraine aura
Papilloedema
What is amaurosis fugax?
Transient complete, sudden unilateral visual loss due to carotid artery atherosclerotic embolism
Causes of acute persistant visual impairment?
Optic Neuritis
Retinal/ Optic nerve ischaemia, arterial thromboembolism of middle or posterior cerebral artery
Causes of eye pain
Corneal abrasion or infection Conjunctivitis Glaucoma Optic Neuritis Sinusitis
Investigations in vision loss
VEP (visual evoked potential) MRI ESR fundoscopy Tonometry (for occular pressure-glaucoma) USS (vitreous haemorrhage)
What are symptoms of retinal detachment?
Detaches from blood vessels:
Flashes and floats
Vision loss
What is a vitreous haemorrhage & what are the causes?
Leakage of blood into vitreous humor, causes vision loss
Caused by DM or trauma due to weakened vessels
What is the risk of MS in people with optic neuritis?
40% get it in 15 years
What is optic neuritis?
Inflammation of optic nerve
What are the causes of Optic Neuritis?
MS GCA Syphilis Lyme B12 deficiency
Symptoms of optic neuritis
- Decreased acuity over hours/days
- Pain on eye movement
- Dyschromatopia (decreased colour vision exacerbated by heat- Uhthoff’s)
Also
Afferent pupil defect
Photopsias (flashes of light)
Treatment of optic neuritis
Steroids and recovery in 6 weeks.
