Abnormal pupil Flashcards
Features of Argyll-Robertson pupil?
Small, irregular pupils?
No response to light by there is a response to accommodate
Handy mnemonic used for Argyll-Robertson Pupil?
Argyll-Robertson Pupil= ARP= Accommodation Reflex Present (ARP)
Pupillary Reflex Absent = PRA
Causes of Argyll Roberston pupil?
DM
Syphilis
An abnormally large pupil has three causes you should know (capsule) …
Pharmacological
Third nerve palsy
Acute glaucoma
(only say ‘Holmes Adie’ having named these first three causes).
An abnormally small pupil has which one essential cause we should know ….(capsule) …..
Horners syndrome.
What is Holmes-Adie pupil?
Benign condition most commonly seen in women. Ddx for dilated pupil
Features of Holmes-Adie pupil?
Unilateral in 80% cases
Dilated pupil
Once the pupil has constricted, remains small for an abnormally long period of time
Slowly reactive to accommodation but very poorly to light
Association of Holmes-Adie pupil?
Usually occurs in young females
Association of absent knee/ ankle tendon reflexes
= “Holme-Adie syndrome”
What’s an RAPD?
Relative afferent pupillary defect, found by the swinging light test
Caused by a lesion anterior to the optic chiasm (optic nerve or retina)
How do you perform the swinging light test?
Shine light into eye :
normal eye: both pupils will constrict appropriately to light (direct and consensual response).
Affected eye: pupil constriction is slow and may be incomplete
Swinging light test:
Shine a light into one eye, swing it into the other eye (3-4 secs in each eye), and so on back and forth.
RAPD swinging test finding: when shine light in the affected eye : both eyes will dilate, or constricts briefly followed by dilatation.
Causes of RAPD
Retinal detachment
Optic nerve- optic neuritis (MS)- most common cause
What is the pathway for the pupillary light reflex?
afferent: retina → optic nerve → lateral geniculate body → midbrain
efferent: Edinger-Westphal nucleus (midbrain) → oculomotor nerve
Ddx of abnormal pupils?
Miotic ‘small’ pupils
* Drugs e.g. opiods, pilocarpine for acute glaucoma
* Horners syndrome (sympathetic pathway disruption
* Argyll-Robertson pupil
Large ‘mydriatic’ pupil
* Third nerve lesions e.g. PCA anyeurysm
* Holmes-Adie pupul
* lesion in eye e.g. acute glaucoma
* drugs; atropine, adrenaline
Other
* Inflammation - Uveitis (posterior synchiae due to adhesions)
Causes of mydriasis? (Large pupil)
Third nerve palsy
Homes-adie pupil
Phaeochromocytoma
Congenital
Traumatic iridologist
Drug causes of mydriasis (large pupil)?
Topical mydriatics - tropicamide, atropine
Sympathomimetic drugs - amphetamines, cocaine
Anticholinergic drugs - tricyclic antidepressants
