brief description of different types of pupillary abnormalities.

1. PUPILLARY ABNORMALITIES
DR.AHMED USMAN KHALID
PG-RESIDENT
HMC

2. CONTENT:
•ANATOMY
•AFFERENT PUPILLARY DEFECT
•HORNER SYNDROME
•ADIE PUPIL
•ARGYLL ROBERTSON PUPIL
•TECTAL PUPILS
•HUTCHINSON PUPIL
•MCQs

4. LIGHT REFLEX:
•Mediated by retinal photoreceptors and four neurons:
1. Sensory
2. Internuncial
3. Preganglionic motor
4. Postganglionic motor

6. Afferent pupillary defect:
AbsoluteAPD:
•Amaurotic pupil – complete optic nerve lesion.
•NPL eye.
•Both pupils equal in size.
•Near reflex is normal in both eyes.

8. Relative afferent pupillary defect:
•Marcus-gunn pupil – incomplete optic nerve lesion.
•Swinging flashlight test.
•Key point:
 afferent (sensory) lesions - pupils equal in size
 efferent (motor) lesions - anisocoria

10. Horner syndrome:
•Oculosympathetic palsy
•Sympathetic supply involves three neurons:
1. Central
2. Preganglionic
3. Postganglionic

12. • stroke
• Brainstem tumor or demylination
• Syringomyelia
• Cervical spinal cord lesion
• Diabetic autonomic neuropathy
First order
(central)
• Pancoast tumor
• Carotid and aortic aneurysm and dissection
• Thoracic spinal cord lesion
Second order
(preganglionic)
• Internal carotid artery dissection
• Nasopharyngeal tumor
• Cavernous sinus mass
• Otitis media
Third order
(postganglionic)

13. Presentation:
•Mostly unilateral
•Bilateral – cervical spine injuries, autonomic diabetic neuropathy
•Acute painful horner – carotid dissection should be suspected

14. Presentation:
•Mild ptosis (1-2 mm) – weakness of mullers muscle.
•Miosis – unopposed action of sphincter pupillae.
•Hypochromic heterochromia – congenital horner.
•Reduced ipsilateral sweating – lesion below superior cervical ganglion.

15. Pharmacological tests:
Apraclonidine test 0.5 or 1%:
•Diagnostic test
•Penetrates blood-brain barrier
•Result : horner pupil will dilate but normal pupil is unaffected.
•Explanation : alpha-1 receptors are upregulated in denervated dilator pupillae.

16. Cocaine 4% :
•Result : normal pupil will dilate but horner pupil will not.
•Explanation: it blocks the re-uptake of noradrenaline at postganglionic nerve
endings.

18. Phenylephrine 1%:
•To distinguish between pre and post-ganglionic lesions.
•Result: In postganglionic lesion, horner pupil will dilate and ptosis may be
temporarily relieved.
•Explanation: In postganglionic horner, dilator pupillae muscle develops
denervation hypersensitivity to adrenergic neurotransmitters.

19. Hydroxyamphetamine 1%:
•Slightly more sensitive than phenylephrine.
•Result: normal or preganglionic horner pupil will dilate.
•Explanation: it potentiates the release of noradrenaline from functioning
postganglionic nerve endings.

21. Investigations:
•Specialist neurological or neuro-ophthalmological assessment should be sought.
•Acute presentation – emergency
•Mainstay of investigation – imaging ( CT or MR)

22. • MRI brain/spinal cord
central
• CXR
• CT thorax
• Carotid Doppler
• MRI/MRA head/neck
• LN biopsy
preganglionic
• Carotid doppler
• MRI/MRA head/neck
• MRI orbits
• ENT assessment
postganglionic

23. Treatment:
•Underlying cause should be addressed.
•Ptosis surgery can be considered at patient’s discretion.
•Apraclonidine may be helpful as a temporizing measure.

24. Adie(tonic) pupil:
•Mechanism: denervation of postganglionic parasympathetic supply to sphincter
pupillae and ciliary muscle.
•May follow a viral illness.
•Site of dysfunction: ciliary ganglion
•Presentation is unilateral in 80% cases.

25. Presentation:
•Large, regular pupil.
•Both direct and consensual light reflex is absent or sluggish.
•Accomodation is slow and prolonged.
•In long standing cases, pupil may become small – little old adie.

26. Associations:
•Diminished lower limb deep tendon reflexes – Holmes-adie syndrome
•Excessive sweating – Ross syndrome
•Orthostatic hypotension

27. Pharmacological testing:
•Instillation of 0.1-0.125% pilocarpine into both eyes.
•Adie pupil will constrict due to denervation hypersensitivity.
•Bilateral tonic pupils – syphilis serology should be done.

28. Argyll Robertson pupil:
•Dorsal midbrain lesion
•Light reflex is lost but accommodation reflex is present (light-near dissociation)
•Bilateral small pupils.
•Caused by neurosyphillis.

29. Pharmacological testing:
•Distinguised from adie pupil by pilocarpine 0.1%
•Adie pupil constricts but Argyll pupil DON’T.

31. Tectal pupils:
•Component of dorsal midbrain syndrome.
•Light-near dissociation
•Pupils are dilated in both dim and bright light.
•No effect of pilocarpine 0.1%

32. causes of light-near dissociation

33. Hutchinson’s pupil:
• Seen in comatose patients.
• Dilated, unreactive pupil.
• Cause: expanding intracranial mass causing 3rd nerve compression.

34. MCQs

35. 1. A small non-reactive pupil with iris atrophy but no ptosis suggests:
A) Horner syndrome
B) Argyll-Robertson pupil
C) Pilocarpine exposure
D) Retinal detachment
E) Optic nerve lesion

36. 2. A patient has developed a Horner’s syndrome due to dissection of the
right carotid artery. Cocaine drops are applied to each eye. Which one of
these statements is correct?
A) The right pupil dilates because of denervation hypersensitivity
B) The right pupil dilates because of stimulated release of noradrenaline
C) The right pupil does not dilate because of blockage of alpha receptors
D) The right pupil does not dilate because of lack of noradrenaline in the synaptic
cleft

37. 3. The following signs are useful in distinguishing between the
congenital and acquired form of Horner's syndrome:
A) absent light reflex of the affected eye
B) lighter iris colour of the affected eye
C) decreased facial sweating of the affected side
D) dilatation of the affected pupil with 10% cocaine
E) dilatation of the affected pupil in response to 1% adrenaline

38. 4. The right pupil is dilated and the result of the swinging light test is as
shown below. The following may account for the findings:
A) examination is normal
B) patient may have a right optic atrophy
C) patient may have a left optic atrophy
D) patient may have advanced left glaucoma
E) patient may have a right macular hole

39. 5. Pupil reflex fibres pass from retina to Edengar Westphal nucleus:
A) Directly.
B) Via visual cortex.
C) Via hypothalamus.
D) Superior colliculus.
E) Via frontal gaze center.