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By
Dr. Mirza Shafiq Ali Baig
Dr. Farnaz Siddiqui
OCULAR MOVEMENTS
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Ductions
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Monoocular movements around the axes of Fick.
Adduction, abduction, elevation, depression, intorsion and
extorsion.
Version
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Binocular, simultaneous ,conjugate
movements in the same directions.
Dextroversion and levoversion
Dextroelevation and levoelevation
Dextrodepression and levodepression.
OCULAR MOVEMENTS
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Vergences
– Binocular, simultaneous, disjugate or disjunctive movements in
opposite directions.
– Convergence and divergence.
ANATOMY OF THE EOM’S
Six Extraocular muscles surround each eye:
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Medial Rectus
Lateral Rectus
Superior Rectus
Inferior Rectus
Superior Oblique
Inferior Oblique
ANATOMY OF THE EOM’S
Medial Rectus
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Origin: Annulus of Zinn
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Insertion: 5.5mm behind the nasal limbus
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Action: Adduction
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Nerve Supply: Oculomotor nerve
Lateral Rectus
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Origin: Annulus of Zinn
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Insertion: 6.9mm behind the temporal limbus
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Action: Abduction
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Nerve Supply: Abducent nerve
Anatomy Of The EOM’s
Superior Rectus
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Origin: Annulus of Zinn
Insertion: 7.7mm behind the superior limbus
Action: Elevation, adduction and intorsion.
Nerve Supply: Oculomotor nerve
Inferior Rectus
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Origin: Annulus of Zinn
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Insertion: 6.5mm behind the inferior limbus
Action: Depression, adduction and extorsion.
Nerve Supply: Oculomotor nerve
ANNULUS OF ZINN
ANATOMY OF THE EOM’S
Superior Oblique
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Origin: Superomedial to the optic foramen
Insertion: Upper temporal quandrant of globe.
Action: Intorsion, depression, abduction.
Nerve Supply: Trochlear nerve
Inferior Oblique
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Origin: Behind the orbital rim lateral to the lacrimal sac.
Insertion: Lower temporal quadrant of globe.
Action: Extorsion, elevation, abduction.
Nerve Supply: Oculomotor nerve
STRABISMUS
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Misalignment of the visual axes of the two eyes
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Classification
– Pseudostrabismus
– Heterophoria
– Heterotropia
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Concomitant squint
Incomitant squint
PSEUDOSTRABISMUS
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Prominent epicanthal fold
Hypertelorism
No treatment required
Tendency of the eyes to deviate when fusion is blocked.
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Esophoria (Inward imbalance)
Exophoria (Outward imbalance)
Hyperphoria (Upward imbalance)
Hypophoria (Downward imbalance)
HETEROTROPIA
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Manifest deviation in which the visual axes do not intersect at the point
of fixation.
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Esotropia (Inward deviation)
Exotropia (Outward deviation)
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Hypertropia (Upward deviation)
Hypotropia (Downward deviation)
CONCOMITANT SQUINT
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The variability of the angle of deviation is within 5 Δ in
different horizontal gaze positions.
Angle of the deviation varies in various positions of the gaze as the
result of abnormal innervation or restriction.
SIGN and SYMPTOMS
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Deviation of eye
Loss of vision
Eyeache / strain
Diplopia
Refractive errors
Headache
Head tilt
ESOTROPIA
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Classification:
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Non accomodative
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Infantile Esotropia
Microtropia
Near Esotropia
Distance Esotropia
Acute Esotropia
Consecutive Esotropia
Sensory Esotropia
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ACCOMODATIVE
1. Refractive
. fully accommodative
. partially accommodative
2. Non-refractive
. with convergence excess
. with accommodation weakness
3. Mixed
Esotropia
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Infantile Esotropia
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Deviation within first six months of life with no significant refractive
errors and no limitation of ocular movements.
Angle is large (>30Δ)
Fixation is alternating in primary position
Cross fixation in side gaze
Nystagmus
Infantile Esotropia:
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The refractive error is usually normal for the age of the child
(about +1.50 D).
Inferior oblique overaction may be present initially or develop
later.
Poor potential for BSV.
ESOTROPIA
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Refractive accommodative Esotropia
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a physiological response to excessive hypermetropia and is
beyond the patient's fusional divergence amplitude.
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The deviation presents at about the age of 2.5 years, with a
range of 6 months to 7 years. The two types are:
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Fully accommodative, which is completely eliminated by
correction of the hypermetropic refractive error.
Partially accommodative, which is only partially eliminated
by correction of hypermetropia.
ESOTROPIA
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Non Refractive accommodative Esotropia
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Associated with high AC/A ratio.
Unit increased of accomodation accompanied by
disproportionally large increase of convergence.
The two types are:
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Convergence excess
Accommodation weakness
EXOTROPIA
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Constant
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Congenital
Sensory
Consecutive
Intermittent
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divergence excess (worse for distance)
convergence weakness (worse for near)
basic exotropia (same for distance and near)
STRABISMUS DIAGNOSIS
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Patient History
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Probable time of onset of strabismus
Nature of the onset (sudden or gradual)
Frequency of deviation (constant or intermittent)
Change in size or frequency of the deviation
Which eye is strabismic
Presence or absence of diplopia and other visual symptoms or
signs
History of neurologic, systemic, or developmental disorders
Birth history
Family history of strabismus
Previous treatment, if any, and the type and results of such
treatment.
STRABISMUS DIAGNOSIS
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OCULAR EXAMINATION
– Visual Acquity
– Light reflection tests
– Cover test
– Dissimilar image test
– Binocular single vision test
– Refraction
– Fundoscopy
STRABISMUS DIAGNOSIS
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Visual Acquity:
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Testing in preverbal children
– Fixation and following
– Comparison between the behavior of two eyes.
– Fixation behavior
– Rotation Test
– Preferential looking test
– Pattern visual evoked potential
Testing in verbal children
– Crowded kays picture
– Keeler logMAR
– Sheridan Gardiner test
– Sonkensen Crowded test
STRABISMUS DIAGNOSIS
– Light Reflection test
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Hirshberg’s test
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Detect gross heterotropia
Normal reflex
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Just nasal to center of the pupil
Abnormal reflex
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Border of the pupil (15deg or 30 prism D)
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Limbus (45deg or 90 prism D)
In between border and limbus (30 deg or 60
prism D)
Krimsky’s Test
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Place prism in front of deviated eye until light reflex is
symmetrical
Strabismus Diagnosis
– Cover Tests
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Cover-uncover test
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Cover component
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Detects heterotropias
Cover straight eye
Look at uncovered deviated eye (movement
indicate tropia)
Uncover component
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Detects heterophorias
Uncover straight eye
Look at uncover eye for deviation and refixation
Strabismus Diagnosis
– Alternate cover-uncover test
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Detects heterophorias
Alternate cover and uncover both eyes
Look for uncover eye for movements
– Alternate prism cover test
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Measures total deviation (tropias and phorias)
Prism over deviated eye and alternate cover each eye until
no movement
Strabismus Diagnosis
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Binocular Single Vision Test
– Base out prism test
– The Worth’s four dot test
– Bagolini strilated glasses test
– The synoptophore
– Stereopsis tests
• Titmus test , TNO, random dot, lang test and frisby plates
STRABISMUS DIAGNOSIS
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Refraction
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Cycloplegic refraction
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Paralysis of ciliary muscle to neutralize the affect of
accommodation
Drug used are Cyclopentolate and Atropine
Fundoscopy
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Exclude ocular pathology
– Macular scarring
– Optic disc hypoplasia
– Retinoblastoma
STRABISMUS TREATMENT
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Why we Treat
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Restore BSV
Correct abnormal head posture
Treat diplopia and confusion
Correct misalignment
Treatment options:
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Refraction correction
Occlusion therapy
Orthoptic exercises
Prism in glasses
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Surgery
Botulinum toxin chemodenervation
STRABISMUS TREATMENT
STRABISMUS TREATMENT
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Surgery
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Weakening procedures
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Recession
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Slackens the muscle by moving it away from the
insersion
Disinserted muscle is sutured to the scalera behind
its original insertion
Disinsersion or myectomy
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Detaching the muscle from its insertion without
reattachment
Posterior fixation sutures
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Suture the muscle belly to the sclera posteriorly so
as to decrease the pull of the muscle in its field of
action
STRABISMUS TREATMENT
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STRENGTHENING PROCEDURES
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Resection
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Shortens the muscle to enhance to effective pull
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Sutures are tied into the muscle behind its insertion
Muscle anterior to the suture is excised and the cut end is
reattached to the original insertion
Tucking
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Tenden of superior oblique in congenital
fourth nerve palsy
Advancement
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Muscle advancement nearer to the limbus.