Neuroopthalmology Flashcards
What does 3rd CN innervate
All except superior oblique and lateral rectus
What supplies superior oblique
4CN
What supplies lateral rectus
6
Causes of optic disc swelling
-Local ocular causes: choroiditis, retinitis, vasculopathies including retinal vein occlusion
-INflammation of the optic nerve (optic neuritis)
-Systemic inflammation- sarcoidosis, arteritis anterior ischaemic optic neuropathy
-Systemic vascular disease- systemic HTN, non-arteritis anterior ischaemic optic neuropathy, CHF
-haematological malignancies
-Iatrogenic
-Raised ICP: papilloedema
What is optic neuritis
Inflammation of the optic nerve either limited to optic nerve head or involving adjacent retina as well.
Cause of optic neuritis
Demyelination. May be the presenting feature of multiple sclerosis.
-Other causes: compressive optic neuropathy, vasculitis, sarcoidosis, syphilis
CLinical features of optic neuritis
Retro-bulbar pain on eye movement
Globe tenderness
Visual acuity, colour vision (red desaturation), visual field defects
RAPD
Management optic neuritis
IV methylprednisolone
Two types of anterior ischaemic optic neuropathy
Arteritis (inflammatory)
on arteritis (non-inflammatory)
What is arteritic anterior ischaemic optic neuropathy
Visual loss due to inflammatory infarction of posterior ciliary arteries of ophthalmic artery
Secondary to GCA, polymyalgia rheumatica
Presents with temporal headache with jaw claudication, scalp tenderness, weight loss, myalgia
Management of arthritic anterior ischaemic optic neuropathy
`Urgent treatment with high dose steroids followed by long term maintenance over 2-3- years
Temporal artery biopsy within 2 weeks of treatment
What is non arteritic anterior ischaemic optic neuropathy
Presentation
Visual impairment associated with occlusion of optic nerve head circulation
-inflammatory markers not raised.
-Associated with HTN, diabetes, hyperlipidaemua, post surgical hypotension, radiation
Sudden onset blurred vision, no other associated symptoms
reduced vision and altitudinal field defect
Fundoscopy shows
What is papilloedema
Optic disc swelling due to raised ICP bilaterally
presentation of papilloedema
Transient visual obscurations precipitated by change in posture or straining, headache worse on lying down, pulsatile tinnitus
Visual acuity normal
An enlarged blind spot with gradual progressive field loss with eventual atrophic changes in chronic stage
Causes of papilloedema
Intracranial space occupying lesions
Intracranial bleed
Cerebral abscess
Post-traumatic hematoma/oedema
Aqueductal stenosis
Malignant hypertension
Drug induced (indomethacin, vitamin A, nitrofurantoin etc )
Systemic disease e.g. Addisons disease
Nutritional: vitamin B deficiency, folate deficiency
Idiopathic: benign intracranial hypertension
