Ophthalmology 7 - Pupil Disorders Flashcards
pupil constriction how
circular muscles in iris stimulated by parasympathetic nerves using ACh
fibres travel along oculomotor nerve
pupil dilation how
dilator muscles around iris stimulated by sympathetic system using adrenaline
irregular pupil cause
trauma to sphincter muscles e.g. from surgery
anterior uveitis and mis shapen pupil
from adhesions
acute angle closure glaucoma pupil shape change
ischaemic damage to iris muscles and abnormal shape (vertical oval)
rubeosis iridis
neovasc of iris
distorts shape
usually diabetes
coloboma
congential weird iris shape
tadpole pupil
spasm in iris segment
temporary
migraine assoc
myadriasis (dilated pupil) causes
third nerve palsy Holmes-Adie syndrome raised ICP congenital trauma stimulants anitcholinergics
miosis causes (constricted pupil)
Horner's syndrome cluster headaches Argyll-Robertson (neurosyphilis) Opiates Nicotine Pilocarpine
third nerve palsy
ptosis
dilated fixed pupil
divergent strabismus
strabismus = squint
oculomotor nerve pathway
travels through cavernous sinus close to posterior communicating artery
causes of third nerve palsy, pupil-sparing
diabetes
hypertension
ischaemia
causes of third nerve palsy (complete)
idopathic tumour trauma cavernous sinus thrombosis posterior communicating artery aneurysm raised ICP
Horner syndrome
ptosis
miosis
anhydrosis
damage to sympathetic nervous system
may have sunken eye too
central causes x 4 of Horner’s syndrome
stroke
MS
swelling
syringomyelia
pre-ganglionic causes x4 Horner’s syndrome
tumour (Pancoast)
trauma
thyroidectomy
top rib (false rib extra)
post ganglionic causes x 4 Horner’s syndrome
cartoid aneurysm
carotid dissection
cavernous sinus thrombosis
cluster headache
explain why pre/post ganglion is relevant in Horner’s
ganglion is at base of neck
so pre ganglion will be affected by lower neck pathology, post will be above + near carotid
anhydrosis patterns in Horner’s syndrome
central lesion - no seating in arm and trunk as well
pre gang - only in face
post gang - NONE
testing for Horner syndrome
check no heterochromia (in which case may be congential )
cocaine eye drops - no pupil reaction, should dilate
0.1% adrenaline eye drops would dilate Horner’s but not other pupil
Holmes Adie
Argyll Robertson pupil
HA pupil - unilateral dilated sluggish pupil
may be viral cause
AR pupil - neurosyphilis - constricted pupil that accommodates to focus but doesn’t react to light
