Acute visual disturbance 4 - anisocoria

Question 1

anisocoria means

Answer 1

unequal pupils
relatively common

Question 2

how different do the pupils have to be

Answer 2

difference in pupil size >1mm

Question 3

anisocoria may be due to

Answer 3

impaired dilation (sympathetic)
or impaired constriction (parasympathetic)

causes range from benign to life threatening

Question 4

how do you know which is the problem eye

Answer 4

Question 5

what should you do if the anisocoria gets worse under bright light

Answer 5

third nerve palsies cause problems with ocular motility, the eye turns down and out and there is ptosis
if this features are not present there may be a different condition called Adie’s tonic pupil

Question 6

what are you concerned about if the anisocoria gets worse under dim light

Answer 6

Question 7

constriction is

Answer 7

parasympathetic

Question 8

dilatation is

Answer 8

sympathetic

Question 9

sympathetic pathway

Answer 9

three order neutron pathway
1. hypothalamus -> ciliospinal centre of budge (C8 - T2)
2. -> lung apex & ICA -> superior cervical ganglion (carotid bifurcation)
3. ICA & cavernous sinus -> nasociliary nerve (CN V) -> dilator muscle, Muller muscle and lower eyelid smooth muscle

Question 10

parasympathetic pathway

Answer 10

four-order neutron pathway
1. retinal ganglion cells -> optic nerve, chiasma, tract -> bilateral pretectal nuclei (dorsal midbrain)
2. -> bilateral EW nuclei
3. -> CN III -> cavernous sinus, superior orbital fissure & ipsilateral cilliary ganglion
4. -> post ganglionic short ciliary nerves -> pupil sphincter and ciliary muscles

Question 11

HxPC of anisocoria

Answer 11

may be asymptomatic
there may be glare (if one pupil is dilated), impaired accomodation
may be chronic or sudden onset
associated symptoms may include headache, ptosis, diplopia, neck pain, focal nuerology, pulsatile tinnitus

Question 12

POHx (past ocular history)

Answer 12

uveitis (can cause abnormal pupil, but this is not likely to be affected by dim or bright light)
ocular or head/neck surgery

Question 13

medication Hx

Answer 13

atropine or pilocarpine eye drops
sublingual atropine, nasal decongestants

Question 14

what examinations should you do

Answer 14

1. visual Acuity
2. visual Fields
3. pupil Reflexes
4. Opthalmoscopy
5. Colour vision

AFROC

Question 15

ptosis and strabismus indicates

Answer 15

third nerve palsy

Question 16

proptosis indicates

Answer 16

orbital tumour

Question 17

if there is anterior chamber cells, and posterior synechiae

Answer 17

uveitis

Question 18

if theree is sectoral palsy and vermiform movements

Answer 18

adie’s

Question 19

heterochromia may indicate

Answer 19

congenital horner’s

Question 20

what are some things you might see on a list lamp

Answer 20

structural defects, anterior chamber cells, posterior synechiae
sectoral palsy and vermiform movements
heterochromia

Question 21

anisocoria greater in the dark

Answer 21

sympathetic lesion, may be Horner;s syndrome, uveitis, mechanical

Question 22

how do you confirm if it is Horner’ syndrome

Answer 22

use apraclonidine
this will cause dilatation in Horner’e due to denervation sensitivity (alpha-1 effect predominates over alpha-2)

Question 23

anisocoria greater in the light

Answer 23

parasympathetic defect
may be caused by third nerve palsy, adie’s trauma, pharmacological

Question 24

how do you confirm Adie’s

Answer 24

low dose pilocarpine (0.1%) causes constriction in Adie’s pupil from hypersensitivity due to up regulation of cholinergic receptors

Question 25

how to figure out the cause of a anisworia greater in light

Answer 25

Question 26

physiological unequal pupil sizes

Answer 26

up to 20% of the population have uneven pupil sizes <1mm difference the inequality will persist in light and dark may be intermittent, persistent or self resolving

Question 27

oculomotor nerve palsy

Answer 27

third nerve palsy depressed and out turned eye a third nerve palsy does not always have pupil involvement pupil involvement indicates that there may be an aneurysm of the posterior communicating artery causing the third nerve palsy

Question 28

why does pupil involvement in a third nerve palsy call for concern

Answer 28

a third nerve palsy does not always have pupil involvement pupil involvement indicates that there may be an aneurysm of the posterior communicating artery causing the third nerve palsy requires prompt imaging

Question 29

aetiology of oculomotor palsy

Answer 29

microvascular, aneurysm, tumour, trauma, infiltrative (e.g. leukaemia) most cases without pupil involvement are ischameic (hypertension, diabetes etc.)

Question 30

presentation of occulomotor nerve palsy

Answer 30

diplopia, ptosis, pain, pupil involvement eye turned down and out unable to adduct, infraduct, supraduct

Question 31

DDx for oculomotor nerve palsy

Answer 31

myasthenia gravis thyroid orbitopathy giant cell arteritis

Question 32

prognosis of oculomotor nerve palsy

Answer 32

ischameic cases often resolve within 3 months

Question 33

aetiology Horner's syndrome

Answer 33

central (first order): CVA, demyelination, tumour preganglionic (second order): apical lung CA, mediastinal aneurysm, neck/thoracic surgery postganglionic (third order): ICA dissection, cavernous sinus lesions (thrombosis, tumour etc.)

Question 34

presentation of Horner's syndrome

Answer 34

ptosis, mitosis, anhidrosis, ocular redness, asymmetric facial flushing systemic neurological signs and symptoms

Question 35

DDx of Horner's syndrome

Answer 35

physiological anisocoria, involutional ptosis, CN III palsy, chronic Adie pupil

Question 36

management of Horner's syndrome

Answer 36

clinical diagnosis confirmed with apraclonidine acute painful Horner's (ICA dissection) = emergency other management based on aetiology

Question 37

what do you do for acute painful Horner's

Answer 37

ICA dissection emergency CTA/MRA and anticoagulation

Question 38

prognosis of Horner's syndrome

Answer 38

this depends on the aetiology

Question 39

aetiology of Adie's tonic pupil

Answer 39

- ciliary ganglion damage -> postganglionic parasympathetic denervation -> mydriasis worse in light (sluggish light reflex) - idiopathic, post-viral, trauma including surgery, migraine, tumour, VZV, EtOH

Question 40

presentation of Adie tonic pupil

Answer 40

mainly unilateral, F>M, approx 30 yo, photophobia, slow dark adaptation, blurriness light near dissociation can happen post virl generally benign