Neuro2 Flashcards
(34 cards)
Causes of a bitemporal hemianopia? Where is the lesion?
Lesion is at the optic chiasm
Usually pituitary adenoma
Meningioma
Craniopharyngoma
Secondary tumour
Causes of a homomynous hemianopia? Where is the lesion
This is a lesion in the contralateral optic tract or optic radiation
- Cause is a primary or secondary tumour
OR infarction
Lesion causing a homomynous hemionopia but sparing of the macula (central vision spared). Location? Cause?
Location is at the posterior cerebral artery leading to ischaemia of the visual cortex.
Causes are
primary or secondary tumour
infarction
Inferolateral deviation of the eye with diplopia and ptosis in context of Diabetes?
DIABETIC THIRD NERVE PALSY
Caused by microvascular infarction of the blood supply to the oculomotor cranial nerve; manifests as inferolateral deviation of the eye with diplopia and ptosis; recovery generally occurs over weeks to months, although deficits that are present after six months are usually permanent
Causes of sudden painless visual loss?
VASCULAR
Retinal artery occlusion
Retinal Vein occlusion
GCA
TIA
Stroke
NON VASCULAR
Retinal detachment
Optic Neuritis
Vitreal heamorrhage
Non arteritic ischaemic optic neuropathy
Chronic, gradual painless loss of peripheral vision. Eventually becoming tunnel vision
Chronic Open angle glaucoma
Glaucomatous cupping on fundoscopy (increased size of optic cup)
How does acute angle closure glaucoma present
Acutely Painful
Severe headache
Blurred vision
Nause and vomiting
Hazy cornea
Mid dilated pupil that reacts poorly to light
Red eye
Haloes around lights at night
Extreme weakness
Management of chronic open angle glaucoma
Usually by opthalmologist
- Beta adrenergic blockers
- alpha 2 adrenergic blockers
- carbonic anhydrase inhibitors
Also laser therapy
Surgery - peripheral iridotomy
Management of acute angle closure glaucoma
IV acetazolamide
Pilocarpine eye drops
Urgent referral to opthalmologist via ambulance
Peripheral iridotomy (definitive treatment)
Causes of glaucoma
Primary - genetic/anatomical predisposition,
Secondary - Increased IOP secondary to Trauma, Uveitis, Glucocorticoid therapy, Ocular syndromes like pigment dispersion, vasoproliferative retinopathy
Treatment of dry eyes
Artificial tears
Environmental strategies - humidification of rooms, avoid dry environments, frequent blinking
Patient presents with acute loss of central vision
Wet macular degeneration
Caused by bleed from under macular area from choroidal neovascularised parts of retina
Sudden fading of central vision
- Amsler grid will show central visual distortions
- Fundoscopy through dilated pupil demonstrates retinal haemorrhage - may see drusen
- For urgent same day opthalmological review
Rx - intravitreal anti- VEGF injections
Clinical features of a retinal detachment?
- Increased floaters in the eye
- Increased flashes/photopsias
- Floaters may look like a cobweb or one particularly large one
- PERIPHERAL visual field deficit which can extend and cause unilateral visual loss
- MANAGEMENT
- URGENT referral to emergency department via ambulance for definitive opthalmologic management.
- Treatment - laser or surgery (cryoretinopexy, vitrectomy)
Whats the most common cause of a retinal detachment
Posterior vitreal detachment which leads to a retinal tear.
Also trauma (less common cause)
How does age related macular degeneration present?
Dry AMD
painless distortion in central vision over time.
Amsler grid central distortions
on fundoscopy - macular drusen and pigment changes
- SMOKING is main modifiable risk factor
- Encourage patients to stop smoking.
- No treatment
- Some evidence to suggest vitamin A, C, E have an antioxidant effect which may slow progress.
Clinical features of optic neuritis?
Presents with unilateral painful visual loss
Usually a young person less than 50 years old
Central scotoma
RAPD
Fundoscopy - demonstrates disc oedema/ blurring of outer boundary
Pain in eye, pain on eye movement
Reduced colour (red) vision
Uthoff’s phenomenon - transient worsening in vision with increasing body temperature
Management - MRI and refer to neurologist
Treatment of preseptal or periorbital cellulitis?
Flucloxacillin 12.5mg/kg (up to 500mg) four times daily orally for 5 days.
if delayed hypersensitivity - cephalexin (Same dose)
if Immediate hypersensitivity
Clindamycin 10mg/kg up to 450mg three times a day for seven days
Clinical features of orbital cellulitis
unilateral warmth, swelling and pain surrounding eye
pain on eye movements/restricted eye movements
tender to palpation
May have diplopia, proptosis, opthalmoplegia
URGENT transfer to emergency department
May need IV antibiotics if severe
CT Brain and orbits - as sight threatening
Photopsias and flashes without visual loss
Posterior vitreal detachment
Assess visual acuity and visual fields with confrontational evaluation
Assess fundus - looking for retinal tear
Sudden onset of floaters and flashes with visual loss requires urgent opthalmologtical review
What is Presbyopia
Age related
Reduced ability for the lens to change shape in order to focus on nearby objects
(near vision is affected)
