Pupil disorders Flashcards
Simulation of circular muscles (iris) that constrict the pupil vs dilator muscles that dilate
PNS (CN3) —> Ach
SNS —> adrenaline
How can anterior uveitis change the pupil shape
Cause adhesions in iris (scar tissues)
Acute angle closure glaucoma on pupil shape
Vertical oval (ischaemic damage)
Rubeosis iridis is … it can cause … and is often associated with
- iris neovascularisation
- discord lens shape
- poorly controlled DM, htn
What is coloboma and what can it cause
- congenital eye malformation
- hole in iris —> irregular pupil shape
Tadpole pupil is … and is associated with …
- spasm in iris —> misshapen pupil
- migraines
Causes of mydriasis (dilated pupil)
- third nerve palsy
- holmes-aide syndrome
- raised IC pressure
- congenital
- trauma
- stimulants (cocaine)
- anticholinergics
Causes of miosis (constricted pupil)
- Horner syndrome
- cluster headache
- Argyll-Robertson pupil
- opiates
- nicotine
- pilocarpine
Innervations of third nerve that lead to the abnormalities found in its palsy
- extraocular muscles except LR & SO —> divergent strabismus
- levator palperbae superioris —> ptosis
- PS innervation to iris sphincter muscles —> dilated fixed pupil
Vascular (surgical third) causes of CNIII palsy due to its course through cavernous sinus
- cavernous sinus thrombosis
- PCA aneurysm
CN3 palsy with sparing of PS fibres suggests what type of cause
Microvascular
Are light and accommodation reflexes affected in Horner syndrome
No
Central lesions cause anhidrosis in
- arm
- trunk
- face
Pre-ganglionic lesions cause anhidrosis in
Face
Post-ganglionic lesions cause anhidrosis in
Nowhere
4Ss causes of central lesions
Stroke
MS
Swelling (tumour)
Syringomyelia
4Ts causes of pre-ganglionic lesions
Tumour (pancoast)
Trauma
Thyroidectomy
Top rib
4Cs causes of post-ganglionic lesions
Carotid aneurysm
Carotid artery dissection
Cavernous sinus thrombosis
Cluster headache
Congenital Horner’s is associated with
Heterochromia
How do cocaine eye drops test for horners (also adrenalin eye drops)
Cocaine blocks adrenaline re-uptake —> + adrenaline present normally —> no adrenaline released by nerves in CNIII palsy —> no reaction
Damage to the post-ganglionic PS fibres in Holmes Adie pupil lead to
Unilateral dilated pupil sluggish to react to light with slow dilation following constriction
Holmes Adie syndrome
Holmes adie pupil + absent knee/ankle reflexes
Argyll-Robertson pupil is specific to
Neurosyphillis
Define Argyll-Robertson pupil
Constricted pupil, accommodates when focusing near objects, does not react to light
