Abnormalities of the pupil

1. A PRESENTATION
ON
ABNORMAILITIES
OF THE PUPIL
BY
DR. DANIEL EMEDIONG
WALTER

2. The Pupils
It is a circular aperture at the
centre of the iris that allows light
to enter the retina.
The size of pupil normally varies
between 2 to 4 mm.
The pupil is round in shape and
relatively equal in size.
Miotic pupils are less than 3mm
Mydriatic pupils are greater than
7mm

3. Abnormal Pupils: Anisocoria
Anisocoria means unequal pupils.
If there is a poor reaction to light in one eye and the
anisocoria is more evident in a well lit room, then the
affected pupil is abnormally large.
If there is a good reaction to light in both eyes but a
poor dilation in the dark then the affected pupil is
abnormally small.

4. The Abnormally Large Pupil
Features
There is poor constriction in a well lit room.
Differential diagnosis
Traumatic iris damage
Third cranial nerve palsy
Pharmacological dilation (i.e. dilating drops)
Adie's pupil
iris rubeosis.

5. The Abnormally Small Pupil
Features
There is poor dilation in a dim room.
Differential diagnosis
Physiologically small pupil
Pilocarpine drops
Uvietis with synaechiae
Horner's syndrome.

6. Dilated Pupil of Right Eye

7. Anomalies of Pupillary Reflexes
• Marcus-gunn pupil: It is also known as Related
Afferent Pupillary Defect (RAPD) or pupillary
escape phenomenon.
It occurs in defect of visual pathway anterior to
the chaisma. It consists of:
1.A diminished amplitude to pupillary reaction
2.Pupillary dilation with continuous light
stimulation.
• Bilateral afferent pupillary defects are common
(e.g. patients with optic neuritis), but a bilateral
RAPD cannot exist.

8. Marcus-gunn Pupil

9. Detection : The test for its detection is called
swinging flash light test. Normally, if a
illuminated pen light is alternately directed to
each eye the pupils constrict and do not vary as
the light alternate between the eyes.
In afferent pupillary defect both pupils dilate
when the light is moved from the unaffected
eye to the affected eye. But they constrict
when the light is directed to the normal eye.

10. Causes of Marcus-Gunn Pupil
(RAPD)
Optic neuritis
Ischemic optical disease
Optic nerve damage (Trauma, Radiation,
Tumor)
 Retinal detachment
Severe macular degeneration

11. Diseases Affecting the Pupils
Congenital Abnormalities
Aniridia
Iris Coloboma
Leukocoria
Acquired Structural Abnormalities
Pseudoexfoliation Syndrome
Sphincter Tear
Neurological Abnormalities
Horner’s Syndrome
Adie’s Tonic Pupil
Argyll-Robertson’s Pupil

12. Diseases Affecting the Pupils:
Congenital Abnormalities
• Aniridia: The term Aniridia
implies an absence of Iris.
• In the majority of cases a small
stump of iris tissue exists at the
iris root.

13. Etiology of Aniridia
Aniridia is an congenital anomaly that
develops at approximately twelfth week
of gestation.
Two-thirds of the cases are inherited in
the autosomal dominant fashion. The
remaining one-third of the cases appear
as a result of spontaneous mutation .

14. Ocular signs and symptoms
Photophobia
Corneal opacification
Congenital polar cataracts
Lens dislocations
Progressive Glaucoma
Management
Colored contact lens.
Early goniotomy can be performed to prevent blockage
to trabecular meshwork.
Filtering surgery.
Cyclocryotherapy

15. Diseases Affecting the Pupils
: Congenital Abnormalities
Iris Coloboma: This is an
uncommon congenital
condition characterized by a
unilateral or bilateral partial
iris defect.
• It is a condition where
normal tissues of iris is
missing from birth.
• It creates “Key-hole” or
“Cats-eye” appearance to the
iris.

16. • The eye develops quickly during
the first three months of growth
of a fetus.
• A gap , known as the choroidal
fissure, appears at the bottom of
the stalks that eventually form the
eye.
• This fissure generally closes by the
seventh week of gestation. If it
does not close , a coloboma or
space forms
Etiology of Iris coloboma

17. Signs and symptoms
Missing iris tissue
Reduced vision
Key-hole or cat-eye shaped pupil
Photophobia
Management
Usually there is no cure for coloboma.
Colored contact lens
Surgery

18. Diseases Affecting the Pupils:
Congenital Abnormalities
Leukocoria: Refers to a white
pupillary reflex from the
retina of the eye.
Etiology of Leukocoria
Many conditions cause
leukocoria
• Congenital cataract
• Retinal detachment
• Retinoblastoma
• Endophthalmitis
Leukocoria in the left eye

19. Signs and symptoms
• Vision problems.
• Eye pain.
• Redness of the white part of the eye.
• Bleeding in the front part of the eye.
• Bulging of the eye.
• A pupil that doesn’t constrict when
exposure to the bright light.
• A different color in each iris.
Management
• Leukocoria is managed by treating any other underlying
conditions (Retinal detachment, cataract e.t.c) which are
responsible for the appearance of the white pupil.

20. Acquired Structural
Abnormalities
• Pseudoexfoliation Syndrome: This is
a condition characterized by
deposition of a grey-white fibro
granular extracellular matrix material
deposited on the anterior lens.
• It is seen on the slit-lamp
examination as a fine grey dusting
around the pupil.
• Pupil shape and function are not
affected.
• It is clinically significant due to its
association with glaucoma and its
potential to make cataract surgery
more tricky.

21. Signs and symptoms
• White flaky materials on pupillary border of the iris.
Management
• IOP lowering medications as first line therapy.
• Argon Laser Trabeculoplasty (ALT)
• Selective Laser Trabeculoplasty (SLT)

22. Acquired Structural Abnormalities
Sphincter Tear:
• Iris tear can occur as a
result of blunt or
penetrating trauma and
can also occur during
intraocular surgery.
• Tears may be associated
with Glaucoma and visual
problems.
Tear in the spincter muscle

23. Neurological Abnormalities
Horner’s Syndrome: It is a
syndrome that consists of
miosis, partial ptosis and
endophthalmitis.
• Sometimes associated
with unilateral absence of
sweating of the face of
the affected side
(Anhydrosis).
• In congenital form there
may be associated
heterochromia of iris.

24. Etiology
Horner’s syndrome can be caused by any
interruption in a set of nerve fibers that start in
the part of brain called hypothalamus and travel
to the face and eyes.
Injury to the carotid artery of the brain.
Injury to the nerves at the base of the neck
called the brachial plexus.
Migraine.
Tumor in the top of the lung.
Management
If cosmetically unaccepted, ptosis may be
corrected surgically.

25. Neurological Abnormalities
Adie’s Tonic Pupil
It is a neurological disorder
characterized by a tonically
dilated pupil that reacts slowly
to light but shows a more
definite response to
accommodation.
Cause:
Caused by Postganglionic
parasympathetic pupillomotor
damage
Adie’s Tonic Pupil in the left
eye

26. Signs and symptoms
• Abnormally dilated pupil which doesn’t
constrict in response to light
• Hyperopia due to accommodation paresis
• Photophobia
• Blurry vision
• Facial pain
• Headache
Management
• There is no effective treatment.
• Weak miotics may be helpful
• Near correction may be given to the affected
eye

27. Neurological Abnormalities
Argyll-Robertson’s Pupil
It is a bilateral abnormality
characterized by failure of
the pupils to constrict with
light , but retention of
constriction present with
accommodation

28. Causes
• Neuro-syphilis- here all signs are present.
• Non-syphilitic causes :
Diabetes
Multiple sclerosis
Hemorrhage and tumors involving the pretectal
region
Management
• Syphilis is the major cause of Argyll Robertson pupil.
• Administration of penicillin intravenously is the
method to treat almost all stages of syphilis.

29. References
• Aao neuroophathalmology ..pg 356
• Alberts Principles-occuloplastics and neuro -
Volume III
• Khurana Comprehensive Ophthalmology 6th
edition
• Neuro-Ophthalmology Illustrated 2nd Ed
• ZIA CHOUDHARY : THE PUPIL; PG-439 PDF –1558