SIMPLIFIED

1. PUPIL
Dr.Sandra Mosses
JR1M3

2.  aperture located in the centre of the iris that
allows light to enter the retina
 control the amount of light entering the eye
 ensure optimal vision for the lighting conditions
 pupils should be equal in size, round, regular,
centered in the iris and should exhibit specific
reflex responses PERRLA

3. Size
 normal –2-6 mm in diameter
 ordinary ambient light ---3-4 mm in diameter
Ambient
illuminatio
n
Para
Sympatheti
c
supply
Sympatheti
c
supply

4. PUPIL GAUGE

5. Miosis <2 mm
 Old age
 Hyperopia
 Alcohol abuse
 Neurosyphilis
 Diabetes
 Levodopa therapy
 Horner's syndrome
 Pontine hematoma
Spastic or irritative miosis-- spasm of
the pupillary sphincter
 Corneal/intraocular fbs
 Miotic drops
 Spasm of the near reflex
 Chronic anterior segment
ischemia
 Adie's pupil
Scarring miosis
 Iridocyclitis-- scarring bind the
pupil down to the cornea (anterior
synechia) or lens (posterior
synechia) and cause miosis and
pupillary irregularity
Paralytic miosis-- paralysis of the
Acquired miosis
ophthal
disorders

6. Mydriasis >6 mm
 anxiety, fear, pain
 myopia
 bilateral lesions of the retina /anterior visual
pathways
 midbrain lesions
 cardiac arrest
 cerebral anoxia
 terminal condition

7.  Large pupils were
once considered a
sign of youth and
beauty, and the
anticholinergic
belladonna (Ital. “fair
lady”) alkaloids were
named for their
ability to produce
this effect
 Persons with light
irises have larger
pupils than those

8. Effects of Drugs on the Pupil
 Atropine
 Homatropine
 Scopolamine
 Epinephrine/norepinephr
ine
 Phenylephrine
 Hydroxyamphetamine
 Cocaine
Anticholinergics/sympatho
 Pilocarpine
 Methacholine
 Muscarine
 Physostigmine/neostigmi
ne
 Opiates
 Ergot derivatives
Cholinomimetics/cholineste
MYDRIASIS MIOSIS

9. Shape
 round, with a smooth, regular outline
Abnormalities –
 iritis
 Synechia
 congenital coloboma (a gap in the iris)
 prior trauma
 iridectomy

10. Equality
 reactivity of the normal eye and the consensual light
reflex will ensure pupil size remains equal
 difference of 0.25 mm in pupil size is noticeable
 difference of 2 mm is considered significant
Physiologic anisocoria
 1 mm difference --15% to 20%
 degree of inequality remains about the same in light
and dark
 pupils react normally to all stimuli and to instilled
drugs

11. ANISOCORIA

12. TOURNAY ‘S PUPILLARY
PHENOMENON

13. eccentric pupil
spontaneous, cyclic
displacement of the pupil
from the centre of iris
• local eye disease
• Severe midbrain
disorders
CORECTOPIA IRIDIS (ectopia
pupillae, Wilson's sign)

14. MICROCORIA ---
MEGALOCORIA

15. POLYCORIA--multiple
pupils

16. Double pupil

17. Light
Reflex

19.  Always have the patient fix at a distance
 Normal pupillary light reflex -- brisk constriction
followed by slight dilatation back to an
intermediate state (pupillary escape)
 Escape may occur because of adaptation of the
visual system to the level of illumination
 Responses --prompt, sluggish, or absent, graded
from 0 to 4+

20. Accommodation Reflex
near response, near reflex, accommodation-
convergence synkinesis, near synkinetic triad
THICKENIN
G OF LENS
CONVER
GENCE
OF EYES
MIOSIS

22.  primary stimulus for accommodation is
blurring
 Without the near response, attempting to
focus on a close object would result in
blurred vision or frank diplopia
 Accommodation --contraction of the ciliary
muscle relaxes the zonular fibers,
permitting the lens to become more
convex because of its inherent elasticity---

23. Ciliospinal reflex
 consists of dilation of the pupil on painful
stimulation of the skin of I/L neck
 Local cutaneous stimulation (e.g., scratching
the neck)--activates sympathetics through
connections with the ciliospinal center at C8-
T2 --sympathetic nervous system—dilator
pupillae--I/L pupil dilate
 intact ciliospinal reflex is evidence of
brainstem integrity when evaluating a
comatose patient

24.  Oculosensory /oculopupillary reflex
consists of either constriction of the pupil or dilation
followed by constriction in response to painful
stimulation of the eye or its adnexa
 Piltz-Westphal reaction
pupils normally constrict on attempted lid closure
 Cochleopupillary reflex/Vestibulopupillary reflex
constriction followed by dilation occurs in response to a
loud noise/stimulation of the labyrinthine system
 Psychic reflex
dilate in response to fear, anxiety, mental concentration
because of sympathetic nervous system activity

25. Large Pupils
 pupillary parasympathetics occupy a position on the
dorsomedial periphery of the nerve as it exits the
brainstem
 compressive lesions -- affect the pupil (aneurysm)
 Ischemic lesions-- spare pupil (diabetic third nerve
palsies) because the periphery of the nerve has a better
vascular supply
 This rule is not absolute: pupil-sparing third nerve
palsies have been reported with aneurysms (in up to
10% of cases), as have diabetic palsies involving the
III rd CN palsy
Adie's tonic
pupil

27. PUPIL RULE ---
BARTON
Complete pupil sparing with
otherwise complete and
isolated palsy of CN III is
never due to an aneurysm

28. HUTCHINSON’S PUPIL
 Pupil is involved early
and prominently with
third nerve compression
due to uncal herniation

29. Cavernous sinus
lesions
 ocular sympathetics are involved
along with CN III
 pupil may be midposition
 compression of both CN III and the
pericarotid sympathetics, leaving the
pupil mid-size but unreactive
 should not be mistaken for pupil
sparing

30. Adie's (Holmes-Adie) tonic pupil
 Asymptomatic Young woman suddenly noticing
Unilaterally enlarged pupil
 Pupillary reaction to light absent
 Reaction to near slow but preserved
 Ciliary ganglion or short ciliary nerves or both
 Depressed or absent deep tendon reflexes,
particularly in the lower extremities
 Old adie's pupil --unilateral miosis

31. Small Pupils
HORNER'S
SYNDROME
ARGYLL
ROBERTSON PUPIL

32. HORNER’S SYNDROME [J. F.
Horner]
 Sympathetic dysfunction
Ptosi
s
Miosis Anhidrosis
Apparent
enophthalmo
s
Loss of the
ciliospinal reflex
Ocular
hypotony
Increased
amplitude
of
accommoda
tion
vasodilatio
n in
affected
distributio
n

33.  Small pupil dilates poorly in the dark
 Pupillary asymmetry greater in the
dark than in the light generally means
Horner's syndrome
 The pupil in Horner's syndrome not
only dilates less fully, it dilates less

34.  Ptosis of the upper lid due to denervation of Müller's
muscle is only 1 mm to 3 mm
 The lower lid is frequently elevated 1 mm to 2 mm
because of loss of the action of the lower lid accessory
retractor that holds the lid down (inverse ptosis)
 Resulting narrowing of the palpebral fissure causes
apparent enophthalmos
 Fibers mediating facial sweating travel up the external
carotid--lesions distal to the carotid bifurcation produce
no facial anhidrosis except for perhaps a small area of
medial forehead that is innervated by sympathetic fibers
traveling with the internal carotid

36. FIRST ORDER HORNER'S SYNDROME
 Interruption of the sympathetic pathways between
the hypothalamus and the spinal cord (Wallenberg's
syndrome)
SECOND ORDER HORNER'S SYNDROME
 2nd order neuron lies in the ciliospinal center at C8-
T2
 Lesion involving this portion of the pathway (e.g.,
syringomyelia, C8 root lesion)
THIRD ORDER HORNER'S SYNDROME
 third order neuron lies in the superior sympathetic

38. CAUSES OF HORNERS
SYNDROME
 Brainstem lesions (especially of the lateral
medulla)
 Internal carotid artery thrombosis or
dissection
 Cavernous sinus disease
 Apical lung tumors
 Neck trauma
 Cluster headache
 Isolated manifestation of syringomyelia

39. Behaviour of unequal pupils in light
& dark

40. Reverse Horner's syndrome
(Porfour du Petit syndrome)
 Unilateral mydriasis, facial
flushing and hyperhidrosis
 Due to transient sympathetic
overactivity in the early stages of
a lesion involving the sympathetic
pathways to one eye

41. Pharmacologic testing to assess
level of lesion
 Cocaine drops instilled into the eye can confirm
the presence of Horner's syndrome
 Cocaine blocks the reuptake of norepinephrine
from the nerve terminals, increasing its effect
 With Horner's syndrome of any type, there is
less norepinephrine being released, less
accumulates at the pupillodilator, and cocaine
will fail to dilate the affected pupil

42. Hydroxyamphetamine
 can distinguish a third order from other types of
Horner's syndrome
 release of norepinephrine, but only from intact nerve
endings
 If the third order neuron is intact, as with first or
second order Horner's syndrome, the pupil will dilate
in response to hydroxyamphetamine
 In a third order Horner's syndrome, there are no
surviving nerve endings in the eye to release
norepinephrine and the pupil will fail to dilate

44. Congenital Horner's syndrome
 may cause sympathetic heterochromia iridis
and other trophic changes of the head and
face
Pseudo-Horner's syndrome
 Thompson et al. described a group of patient's
with unilateral ptosis and miosis of unrelated
origin simulating oculosympathetic paresis,
 majority of patients had simple, physiologic
anisocoria accompanied by incidental ptosis
due to blepharochalasis

45. Argyll Robertson Pupil
 small (1 mm to 2 mm)
 irregular in outline
 light near dissociation --react poorly or not at all
to light, but very well to near
 Anterior visual pathway function must be
normal
 generally bilateral and symmetric
 lesion lies in the periaqueductal region,
pretectal area and rostral midbrain dorsal to the

46. Mechanism:
 Pupillary light reflex fibers enter the
dorsal brainstem
 Near response fibers ascend to the EW
nucleus from the ventral aspect
 Disorders that affect the dorsal rostral
brainstem may affect the light reaction but
leave the near reaction intact

47. CAUSES OF LIGHT NEAR
DISSOCIATION
 Neurosyphilis (mandate serological testing if present)
 Diabetic autonomic neuropathy (tabes diabetica)
 Myotonic muscular dystrophy
 Amyloidosis
 Adie's pupil
 Lyme disease
 Chronic alcoholism
 Chiasmal lesions
 Sarcoidosis
 Multiple sclerosis (MS)
 Aberrant regeneration of CN III

48. Afferent Pupillary Defect
 Key clinical technique in the evaluation
of suspected optic neuropathy
 detect a side-to-side difference even
when the lesion is mild and there is no
detectable difference in the direct light
reflex when testing each eye
individually

49. Swinging flashlight test

50.  OPTIC NERVE LESION--brain detects a relative diminution in light intensity
and the pupil may dilate a bit in response
 The pupil in the other eye dilates as well because the consensual reflex
constricting the pupil in the good eye is less active than its direct reflex
 On moving the light back to the good eye, the more active direct response
causes the pupil to constrict
 On moving back to the bad eye, the pupil dilates because the direct light
reflex is weaker than the consensual reflex that had been holding it down
 As the light passes back and forth, the pupil of the good eye constricts to
direct light stimulation and the pupil of the bad eye dilates to direct light
stimulation
 DYNAMIC ANISOCORIA
 weaker direct response or the paradoxical dilation of the light-stimulated
pupil is termed an afferent pupillary defect (APD), or Marcus Gunn pupil

51. Hippus / pupillary play/
athetosis
 Normal pupils may display constant, small amplitude
fluctuations in size under constant illumination
 no clinical significance, even when pronounced
 but can cause confusion in the evaluation of an
afferent pupillary defect
 Hippus is random; a true APD will be consistent over
multiple trials
 Pay attention to the first movement of the pupil--
consistently a dilation movement the patient has an
APD and not hippus

53. UNSUAL PUPILLARY
ABNORMALITIES
 Paradoxical pupil
 Constrict in darkness
 Congenital retinal and optic nerve disorders
 Mechanism is unknown
 Tadpole pupil
 Pupil intermittently and briefly becomes comma-
shaped

54.  Springing pupil
(benign, episodic pupillary dilation; mydriasis á bascule)
Intermittent, sometimes alternating, dilation of
one pupil lasting minutes to hours
Young, healthy women
Often followed by headache
 Periodic unilateral mydriasis migraine and as an
ictal phenomenon
 Scalloped pupils  familial amyloidosis
 Oval pupilsmajor intracranial pathology /may be a
transient phase in evolving injury to the third nerve
nuclear complex