pupil disorders

Question 1

what can cause abnormal pupil shape?

Answer 1

TRAUMA to sphincter muscles
anterior uveitis
AACG
rubeosis iridis
colobama
tadpole pupil

Question 2

how can trauma to sphincter muscle cause abnormal shape?

Answer 2

sphincter muscle is within iris
can be from cataract surgery

Question 3

what is anterior uveitis?

Answer 3

adhesions - scar tissue within iris
causing irregular pupil shape

Question 4

how can AACG cause irregular shape?

Answer 4

ischaemic damage to muscles of iris and abnormal pupil shape

Question 5

what is rubeosis iridis?

Answer 5

neovascularisation of iris and can distort shape of iris/ pupil

Question 6

what is colobama?

Answer 6

congenital malformation that can cause a hole in iris and irregular pupil shape

Question 7

what is tadpole pupil?

Answer 7

muscle spasm in part of dilator or iris - misshapen pupil

Question 8

what is tadpole pupil associated with?

Answer 8

migraines and horners

Question 9

what is mydriasis?

Answer 9

dilated pupil

Question 10

what can cause mydriasis?

Answer 10

congenital
stimulants - cocaine
anticholinergics - oxybutinin
trauma
third nerve palsy
holmes - adie syndrome
raised ICP
AACG

Question 11

what is holmes-adie syndrome?

Answer 11

rare neuro condition
pupil remains relatively dilated and does not react to light

Question 12

what is miosis?

Answer 12

pupil constriction

Question 13

what can cause miosis?

Answer 13

horner syndrome
opiates
nicotine
pilocarpine
cluster headaches
argyll-roberston pupil

Question 14

what is argyll roberston pupil?

Answer 14

neurosyphilis
remain small and do not react to light

Question 15

what features are seen in third nerve palsy?

Answer 15

ptosis
dilated non-reactive pupil
divergent strabimus

Question 16

what is ptosis?

Answer 16

drooping of eyelid

Question 17

what is divergent strabismus?

Answer 17

squint in affected eye
gives down and out appearance

Question 18

which cranial nerve is the 3rd?

Answer 18

occolumotor

Question 19

what does the CNIII supply?

Answer 19

all extraoccular except lateral rectus and superior oblique

Question 20

how do you assess CNIII?

Answer 20

do 2,3,4,6 together
light reflex
H test
looking distance and back to finger

Question 21

why does third nerve palsy cause eyelid drooping (ptosis)?

Answer 21

CNIII also supplies levator palpedbrae superiosis
this is resposible for lifting eyelid

Question 22

what nervous system does CNIII supply?

Answer 22

parasympathetic - rest and digest

Question 23

why does third nerve palsy cause dilated and non-reactive pupil?

Answer 23

CNIII supplies parasympathetic to circular muscles of iris

Question 24

what can cause typical third nerve palsy?

Answer 24

idiopathic

Question 25

what could cause third nerve palsy without affecting pupil be caused by?

Answer 25

microvascular cause parasympathetic fibres are spared - diabetes HTN - ischaemia

Question 26

what causes a full third nerve palsy?

Answer 26

compression of nerve including compression of parasympathetic fibres - trauma - tumour - cavernous sinus thrombosis - posterior communicating artery aneurysm - raised ICP

Question 27

what is cavernous sinus thrombosis?

Answer 27

blood clot within this sinus sinus located behind eye socket

Question 28

why can posterior communicating artery aneurysm cause full third nerve palsy?

Answer 28

CNIII travels directly from brainstem in a straght line very close to PCA - a aneurysm would push it

Question 29

why can a cavernous sinus thrombosis cause full third nerve palsy?

Answer 29

CNIII travles directly from brainstem to eye in a straght line - blood clot would push against it as the nerve travels through the sinus

Question 30

what is the horner syndrome triad?

Answer 30

ptosis - drooping eyelid miosis - pupil constriction anhidrosis - loss of sweating

Question 31

what sign may also be seen within horners?

Answer 31

enophthalomas sunken eye light and accomodation reflexes not affected

Question 32

what causes horner syndrome?

Answer 32

damage to sympathetic chain

Question 33

what type of ganglion nerve are the ones affected within horners?

Answer 33

pre-ganglion - enter from spinal cord at base of neck

Question 34

how can the location of lesion be determined by horner symptoms?

Answer 34

anhidrosis location: arm, trunk and face - central lesions face - pre ganglionic no anhidrosis - post ganglion

Question 35

what are the underlying pathologies for horners? - pre ganglion

Answer 35

4S, 4T 4S: central lesions - Stroke, mS, Swelling (tumours), Syringomyelia (cyst in spinal cord) T: pre ganglionic - Tumour (pancoast), Trauma, Thyroidectomy, Top rib (cervical rib growing above first rib)

Question 36

what is the underlying pathology for post ganglion horners?

Answer 36

4Cs carotid aneurysm carotid artery dissection cavernous sinus thrombosis cluster headache

Question 37

what is congenital horner syndrome associated with?

Answer 37

heterochromia - difference in colour on affected side

Question 38

how can you test for horner syndrome?

Answer 38

cocaine eye drops low dose adrenaline eye drops will dilate pupil in Horner syndrome

Question 39

what is Holmes-addie syndrome?

Answer 39

holmes addie pupil associated with absent ankle and knee reflexes damage to post-ganglion fibres