Pupil Disorders Flashcards
what nervous system division causes pupil constriction? what is the neurotransmitter?
constriction = parasympathetic using acetylcholine as neurotransmitter
what nervous system division causes pupil dilation? what is the neurotransmitter?
dilation = sympathetic using noradrenaline as neurotransmitter
what is a coloboma
congenital malformation of the eye
- hole in iris causing irregular pupil shape
what is rubeosis iridis
neovascularisation in the iris - can distort pupil/iris shape
- associated with poorly controlled diabetes and diabetic retinopathy
what does mydriasis mean
dilated pupil
what does miosis mean
constricted pupil
causes of mydriasis
3rd nerve palsy
Holmes aidie pupil
raised intracranial pressure
cocaine
congenital
caues of miosis
Horners syndrome
Argyll robertson pupil
Opiates
Nicotine
Pilocarpine
signs of CN 3 palsy
eye is down + out
ptosis (drooping of eyelid)
fixed dilated pupil
what does a painful CN 3 palsy suggest
posterior communicating artery aneurysm
caues of CN 3 palsy
diabetes
raised ICP
posterior communicating artery aneurysm
webers syndrome - ipsilateral CN 3 palsy + contralateral hemiplegia
vasculitis
triad of symptoms in Horners syndrome
ptosis, miosis, anhydrosis
what causes Horners syndrome
damage to sympathetic nervous system
central: stoke, MS, syringomyelia, tumours
post ganglionic (no anhydrosis): carotid aneurysm, cavernous sinus syndrome, cluster headahce, carotid atery dissection
what is seen in congenital horners syndrome
heterochromia - difference in iris colour on the affected side
what is a Holmes adie pupil
unilateral dilated pupil caused by damage to parasympathetic nerve fibres
- slow to react to light
- slow dilation following constriction
