Acute visual disturbance 2 - optic neuropathies Flashcards
optic neuropathy is
abnormality or damage to the optic nerves from any cause
symptoms of optic neuropathy
visual blurring or loss
or a change in colour vision
disc swelling looks like
is optic neuropathy common
no its not common but its not rare either
optic disc elevation may be
psuedopapilloedema or optic nerve head swelling
optic nerve head swelling may be categorised into
elevated ICP and Normal ICP
elevated ICP causes
papilloedema
which is bilateral optic nerve head swelling from elevated intracranial pressure
ONH swelling with normal ICP - is this unilateral or bilateral?
more commonly unilateral
is elevated ICP usually unilateral or bilateral
bilateral
Hx of optic nerve head swelling
variable visual change
pain (retro- or periocular)
systemic (paraesthesia, weakness etc)
headache, TVOs, diplopia -> raised ICP
age Hx
young - optic neuritis (+/- demyelination)
middle aged - non arteritic ischaemic optic neuropathy NAION (tends to happen in vasculopaths)
elderly - GCA
acute onset minutes/hours
NAION, GCA, trauma
subacute onset hours/days
optic neuritis
gradual onset (months/years)
toxic/nutritional/compressive
examination of papillodaema
loss of clarity of the margin of the optic nerve
drusen looks like
speckles
looks similar to hard exudate
age related
aetiology of GCA
systemic vasculitis of medium/large arteries
causes ischaemia of the optic nerve head
presentation of GCA
> 60 years
temporal pain, jaw claudication, discomfort when chewing food, TVOs/diplopia
fatigue, weight loss, myalgia
chalky white disc swelling, cotton wool spots (infarcts of the retina), may also see central artery occlusion
‘cord like’ tender temporal artery with reduced pulse - palpate this as part of the examination
management of GCA
FBC, ESR, CRP
high-dose steroids
time critical condition, they will lose vision is not treated
temporal artery biopsy to confirm diagnosis
prognosis of giant cell arteritis
if untreated, one third patients will develop contralateral vision loss over days
may involve the aorta, causing aneurysm, dissection or rupture
threat to sight and life
aetiology of papilloedema
bilateral optic disc swelling secondary to raised ICP
prsentation of papilloedema
headache (postural), vomiting, visual disturbance, pulsatile tinnitus
DDx of papilloedema
tumour, malignant HTN, venous sinus thrombosis, meningitis, idiopathic intracranial hypertension
management of papilloedema
BP, full neurological exam
MRI/CT head
LP (when SOL excluded)
idiopathic intracranial hypertension is a cause of
a cause of papilloedema
aetiology og idiopathic intracranial hypertension
elevated ICP without identifiable cause
usually female of child bearing age, high BMI, may or may not be on the OCP
management of idiopathic intracranial hypertension
MRI/MRV (exclude SOL/venous sinus thrombosis), then LP
medical: weight loss, salt restriction, acetazolamide, topiramate
surgical: nerve fenestration, neurosurgery (stent), bariatric
prognosis of idiopathic intracranial hypertension
variable depending on management of ICP, BMI
sectoral optic nerve oedema
non-arteritic ischeamic optic neuropathy aetiology
crowded optic nerve head configuration and small vessel arteriosclerosis
presentation of non-arteritic ischameic optic neuropathy
> 50 years
vascular risk factors, sleep apnoea, symptoms felt on waking caused by nocturnal hypotension
sectoral disc swelling and altitudinal field loss (top or bottom field loss)
management of non-arteritic ischaemic optic neuropathy
vascular risk factors, avoid BP meds nocte (this may cause nocturnal hypotension)
prognosis of non-arteritic ischameic optic neuropathy
VA remains status or improves slightly in majority
15% risk to fellow eye within 5 years
optic neuritis on MRI
unilateral optic nerve looks thicker, wider, enhanced on MRI
optic neuritis aetiology
immune mediated inflammation +/- demyelination (risk factor for multiple sclerosis)
younger patient
often preceding viral illness with neuropathic presentations
presentation of optic neuritis
20-45 yo, recent viral illness
+/- neurological symptoms
known MS
DDx of optic neuritis
idopathic, infective, inflammatory, autoimmune/demyelination
management of optic neuritis
MRI brain/spine (T2 hyper intense lesions)
bloods +/- LP after neuroimaging to rule out infection
high dose steroids hasten recovery
immunomodulatory treatment
prognosis of optic neuritis
90% improve to near normal VA in weeks
risk of development of MS (38% of MRI- and 56% of MRI+ at 10y)
compressive tumours
gradual, progressive
Ddx: meningioma, pituitary adenoma, aneurysm, thyroid eye disease
infiltrative issues
subacute - weeks/months
Ddx: lymphoma, leukaemia, multiple myeloma, carcinoma
toxic/nutritional issues
gradual onset; social history is relevant
ethambutamol, amiodarone, alcohol, methanol, methotrexate, cyclosporine
summary of conditions
