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
