Approah to Visual Loss Flashcards
Conditions than can cause acute loss of vision and other ‘red flag’ conditions presenting with visual loss
Acute angle closure glaucoma Central Retinal artery occlusion Retinal detachment Giant Cell Arteritis Papilloedema - raised ICP
Causes of Ptosis
- Neurogenic Causes
- Eg: CNIII Palsy, Horner’s Syndrome
- Myogenic Causes
- Eg: Myaesthenia Gravis, Myotonic Dystrophy
- Aponeurotic Causes
- Eg: Involutional
- Mechanical Causes
- Eg: Orbital tumors, oedema, scarring
- Pseudoptosis
- Eg: contralateral lid retraction
- Mitochondrial Disease
- Eg: Chronic Progressive External Ophthalmoplegia
What is a test on examination can differentiate myasthenia gravis as a cause of ptosis?
Ice - test. Ptosis will improve with application of cold. Note, the ptosis will also be bilateral.
Horner’s Syndrome - what are the three features and the clinical correlation
Partial Ptosis, miosis, anhidrosis (lack of sweating).
Due to interruption of the sympathetic nervous system supply to the eye.
Miosis = constricted pupil (i.e. lose dilation)
What are some causes of Horner’s Syndrome?
Interruption of the SYMPATHETIC nerve supply to the eye:
- brainstem stroke/lesion
- brachial plexus lesion
- tumour of lung apex (Pancoast’s tumour)
- lesion of the post-ganglionic neuron
- dissecting carotid aneurysm, carotid artery ischaemia
Pattern of vision loss in Retinitis pigmentosa
annular scotoma
+ typically affects rods = poor night vision.
Presents in young adults
Fundus examination in retinal vein occlusion
hemorrhages
cotton wool spots
macular oedema
+ RAPD and reduced visual acuity on examination
Clinical Presentation of Giant Cell Arteritis
○ Scalp tenderness
○ Headache
○ Jaw claudication
- Acute, unilateral vision loss
Which rheumatological condition is associated with GCA?
Polymylagia rheumatica
How is GCA diagnosed and treated
Requires temporal artery biopsy (+ look for raised ESR).
Mx = high dose steroids
What is the presentation of Optic Neuritis
- reduced colour saturation - often red desaturation
- RAPD
- swollen optic disc (though fundus can look normal in some)
- pain on eye movement
- visual field defect
Causes of Optic Neuritis
- MS = most common cause
- Infection e.g. syphilis, HSV
- autoimmune conditions - SLE, neurosarcoidosis
- IBD
- drug induced - ethambutol, isoniazid
Causes of Optic Neuropathy
Optic Neuropathy = damage to the optic nerve due to any cause.
- GCA/AION
- NAION - patients 50+ at risk, + systemic vascular disease (see small cup-to-disc ratio and altidunal visual field defect)
- compression (e.g. tumour pressing on optic nerve) - slowly progressive. See optic atrophy or oedema, often central scotoma.
other - inflammatory (e.g. SLE, IBD)
- infiltrative (e.g. malignancies such as lymphoma)
- toxic - ethambutol
Causes of cataracts
- Congenital cataract - dx often at birth
- Drugs (steroids, amiodarone)
- Trauma (including intra-ocular surgery)
- Systemic disease
- Diabetes Mellitus, myotonic dystrophy, Wilson’s disease, atopic dermatitis.
Clinical presentation of cataracts
Progressively more blurry - may need to change glasses prescription.
General/diffuse visual decline
Glares, colour less bright
Halos around lights
Opacity of the lens, cloudy, discoloured seen on slit-lamp examination.
Decreased red reflex
Improvement of visual acuity with pin hole
NO distortion of image on Amsler grid
What is the likely condition?
Cataracts
Risk Factors for Macular degeneration
Age related - genetic + environmental. Risk factors - Age - FHx - Smoking - HTN, obesity, hypercholesterol
What is Macular Degeneration?
Painless, irreversible, degenerative eye condition. Associated with the damage and ultimately death of photoreceptors.
What is the appearance of the fundus in a patient with macular degeneration
early - see drusen and/or pigment changes
may see atrophy
exudates, haemorrages
Clinical Presentation of macular degeneration
Central vision loss
Limited vision - particularly at night
Metamorphopsia (grid of straight lines appear wavy) may be present in severe cases.
WET MACULAR DEGENERATION - can occur rapidly over weeks-months
What is a key examination finding in macular degeneration that differentiate it from cataracts?
- distortion of image on Amsler grid
- NO improvement with pin hole
What is the treatment approach in macular degeneration
aim is to detect early and slow progression.
in dry macular degeneration - dietary (antioxidants, lueitin, vitamins) + manage HTN + smoking cessation. However, still progressive with no cure.
Wet macular degeneration
- photodynamic therapy (coagulate leaky vessels)
- anti-VEGF intra-vitreal injections
Painful loss of vision + fixed and mid-dilated pupil. DDx?
This presentation is suspicious for acute-angle closure glaucoma.
Vision may also be blurry
Will also see increased IOP on examination.
What is the clinical presentation of acute-angle closure glaucoma.
Compare this to primary angle closure glaucoma
- painful loss of vision, may have N&V
- blurring of vision
- redness of the eye
- may report halo around lights
POAG = often silent, more chronic. But may have headache, halos, previous ocular disease, FHx
