pupil disorders Flashcards
control of pupil restriction
circular muscles in iris stimulated by parasympathetic NS
oculomotor nerve
control pupil dilation
dilator muscles stimulated by sympathetic NS
causes of abnormal pupil shape
trauma to sphincter muscles anterior uveitis closed angle glaucoma rubeosis iridis coloboma tadpole pupil
Coloboma
congenital malformation
can cause a hole in iris causing irreg shape
tadpole pupil
spasm in segment of iris causing misshapen pupil
usually temporary + assoc with migraines
mydriasis
dilated pupil
miosis
constricted pupil
causes of mydriasis
3rd nerve palsy homes-adie syndrome raised ICP congenital trauma stimulants e.g. cocaine anticholinergics
causes of miosis
Horner's syndrome cluster headaches argyll-robertson pupil opiates nicotine pilocarpine
Third Nerve Palsy - what does it cause
ptosis (drooping upper eyelid)
dilated, non-reactive pupil
divergent strabismus - down and out appearance
oculomotor nerve - travel route
travels through cavernous sinus close to posterior communicating artery
therefore, cavernous sinus thrombosis + posterior communicating artery aneurysm can compress and palsy 3rd nerve
Third Nerve Palsy - with sparing of pupil
microvascular cause - parasympathetic fibres spared
diabetes
hypertension
ischaemia
Third Nerve Palsy - causes of full palsy (i.e full nerve compression)
idiopathic tumour trauma cavernous sinus thrombosis posterior communicating artery aneurysm raised ICP
Horner’s syndrome: triad
ptosis
miosis
anhidrosis
Horner’s syndrome: caused by
damage to sympathetic NS supplying face
journey of sympathetic nerves to face
arise from spinal cord in chest - pre-ganglionic nerves
they enter sympathetic ganglion at base of neck and exit as post ganglionic nerves
post ganglionic nerves travel to head alongside internal carotid artery
Horner’s syndrome: central lesions cause
anhidrosis of arm and trunk as well as face
Horner’s syndrome: pre-ganglionic lesions cause
anhidrosis face
Horner’s syndrome: post-ganglionic lesins
do not cause anhidrosis
Horner’s syndrome: causes of central lesions
stroke
MS
swelling - tumour
syringomyelia
Horner’s syndrome: causes of pre-ganglionic lesions
pancoast tumour
trauma
thyroidectomy
cervical rib
Horner’s syndrome: causes of post-ganglionic lesions
carotid artery aneurysm
carotid artery dissection
cavernous sinus thrombosis
cluster headache
Horner’s syndrome: congenital is assoc with
heterochromia - difference in iris colour on affected side
testing for Horner’s syndrome
cocaine eyedrops - normal eye will dilate but with Horner’s no pupil reaction
adrenalin eye drop - will dilate Horner’s pupil but not a normal one
Holmes Adie Pupil
unilateral dilated pupil , that is sluggish to react to light
with slow dilation of pupil followed by constriction
Holmes Adie Pupil - caused by
damage to post-ganglionic parasympathetic fibres
Holmes Adie Syndrome
holmes adie pupil
absent knee and ankle reflexes
Argyll-Robertson Pupil
neurosyphilis
constricted pupil that accommodates but does not react
