3. 5- KEY FEATURES TO EXAMINE PUPIL
Size
Shape
Position
Color
Symmetry
4. SIZE
Normal Pupil
2mm – 8mm
Size depends on
factors like age,
sleep, refraction, iris
color.
Abnormally Small
Opiods, miotic agents
(pilocarpine).
It is due to the lesion in
sympathetic pathway to
pupil dilator muscle.
Causes:
Horner’s Syndrome
Argyll Robertson pupil
Pontine hemorrhage
Organophosphorus
poisoning
Drugs cholinomimetics,
cholinesterase inhibitors.
Abnormally Large
Dilating drops, CN3 palsy.
It is due to the paralysis of
parasympathetic fibers either
at the origin from pretectal
nuclei and EW nucleus in the
midbrain.
Causes:
Vascular accidents in mid-
brain
Tentorial herniation
CN 3- palsy
Adie’s Tonic pupil
Overdose Glutathamide,
Cocaine
Drugs- anticholinergics,
sympathomimetics
5. SHAPE
Normal
Round/ circular
Tadpol
e
Incarceration of iris
or vitreous in a
surgical wound
Festooned
Adies sectoral
dilation. This is
subtle. Note how
the iris is slightly
more dilated at 2-3
o’clock.
Posterior
synechiae
(adhesions
between the iris
and the lens
capsule)
Irregular
8. SYMMETRY
Normal
<1mm in pupil size
Horners
Syndrome
Ptosis, Miosis,
Anhidrosis
Cranial Nerve 3
Palsy
Pupil is enlarged and
deviated outwards and
downwards
9. RAPD/ Marcus
Gunn Pupil
Usually occurs as a
result of optic nerve
pathology or sever
retinal disease.
Adie’s Pupil
One or both eyes are
abnormally dilated due
to loss of para-
sympathetic innervation
to the iris sphincter and
ciliary muscle.
Argyll Robertson
Pupil
Colloquially known as
“prostitute’s pupil”.
These are the pupils
that do not constrict to
light but will bilaterally
accommodate with the
near response.
11. EXAMINING PUPIL REFLEXES
Direct Reflex
While the patient looks at a
distant target, shine the light
from inferiorly and slightly
temporally.
Normal response:
contraction of pupils capture
by sphincter pupillae
Record the speed of
reaction:
Brisk
Sluggish
Fixed
Consensual
Reflex
While the patient looks at a distant
target, shine the light on one pupil
and notice the reaction in other eye.
Normal response:
Contraction of the contralateral
pupil when light shone in one eye
which should be approximately
equal in velocity and extent to the
direct pupillary response.
Record the speed of reaction:
Brisk
Sluggish
Fixed
12. Near Reflex
Hold the near chart
approximately at 30cm in front
of the patient’s eyes. Observe for
pupillary constriction, which may
take up to 10 seconds in certain
situations.
Triade of things occurring:
Convergence of gaze
Accommodation of lens
Pupillary constriction
Swinging Flash
Light
• To test RAPD / Marcus Gunn pupil
• Use bright hand-held light in a dim room.
• Shine the light in one of the patient’s eyes
and observe for a reaction. After 3-
seconds, rapidly swing the light to the
opposite pupil and observe the reaction.
After 3- seconds swing back to the first
eye and observe again.
A positive RAPD: Pupil dilates when you
move the light from one side to the other.
Sometimes pupil bounce a little and return to
normal constricted size. This is physiologic
and normal.