Strabismus Nizar Al-Hibshi MD Consultant Pediatric

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Strabismus

• Nizar Al-Hibshi MD
• Consultant Pediatric Ophthalmolgy

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Strabismus

• Squint
• Crossed Eyes

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Strabismus

• Definition
• Misalignment of the eyes

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• Points that will be discussed in the lecture
• Anatomy
• Why we treat
• Examination
• ET
• XT
• Syndromes

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• Points that will be discussed in the lecture
• Anatomy
• Why we treat
• Examination
• Esotropia
• Exotropia
• Syndromes

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Anatomy Of The EOMs

• How many?

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Anatomy Of The EOMs

• Six Extraocular muscles surround each eye
• Medial Rectus
• Lateral Rectus
• Superior Rectus
• Inferior Rectus
• Superior Oblique
• Inferior Oblique

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Anatomy Of The EOMs

• What are their actions??

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Anatomy Of The EOMs

• Medial Rectus Action??

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Anatomy Of The EOMs

• Medial Rectus Action??
• Adduction

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Anatomy Of The EOMs

• Lateral Rectus Action??

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Anatomy Of The EOMs

• Lateral Rectus Action??
• Abduction

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Anatomy Of The EOMs

• Superior Rectus Action??

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Anatomy Of The EOMs

• Superior Rectus Action??
• Elevation

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Anatomy Of The EOMs

• Superior Rectus Action??
• Elevation
• Adduction

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Anatomy Of The EOMs

• Superior Rectus Action??
• Elevation
• Adduction
• Intorsion

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Anatomy Of The EOMs

• Inferior Rectus Action??

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Anatomy Of The EOMs

• Inferior Rectus Action??
• Depression

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Anatomy Of The EOMs

• Inferior Rectus Action??
• Depression
• Adduction

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Anatomy Of The EOMs

• Inferior Rectus Action??
• Depression
• Adduction
• Extorsion

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Anatomy Of The EOMs

• Superior Oblique Action??

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Anatomy Of The EOMs

• Superior Oblique Action??
• Intorsion

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Anatomy Of The EOMs

• Superior Oblique Action??
• Intorsion
• Depression

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Anatomy Of The EOMs

• Superior Oblique Action??
• Intorsion
• Depression
• Abduction

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Anatomy Of The EOMs

• Inferior Oblique Action??

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Anatomy Of The EOMs

• Inferior Oblique Action??
• Extorsion

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Anatomy Of The EOMs

• Inferior Oblique Action??
• Extorsion
• Elevation

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Anatomy Of The EOMs

• Inferior Oblique Action??
• Extorsion
• Elevation
• Abduction

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Anatomy Of The EOMs

• The two Obliques are Abductors

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Anatomy Of The EOMs

• The two Obliques are Abductors
• The two Recti are Adductors

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Anatomy Of The EOMs

• The two Obliques are Abductors
• The two Recti are Adductors
• The two Superiors are Intorters

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Anatomy Of The EOMs

• The two Obliques are Abductors
• The two Recti are Adductors
• The two Superiors are Intorters
• The two Inferiors are Extorters

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Anatomy Of The EOMs
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Anatomy Of The EOMs

• Origin
• A common tendinous ring (annulus of Zinn)

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Anatomy Of The EOMs
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Anatomy Of The EOMs

• Insertion

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Anatomy Of The EOMs
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Anatomy Of The EOMs

• Blood supply
• Each muscle is supplied by two Anterior Ciliary
• Arteries except the Lateral Rectus which is only
• supplied by one.

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Anatomy Of The EOMs

• Nerve supply

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Anatomy Of The EOMs

• Nerve supply
• Third
• Fourth
• Sixth

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Anatomy Of The EOMs

• Nerve supply
• Third MR, IR, SR, IO
• Fourth
• Sixth

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Anatomy Of The EOMs

• Nerve supply
• Third MR, IR, SR, IO
• Fourth Superior Oblique
• Sixth

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Anatomy Of The EOMs

• Nerve supply
• Third MR, IR, SR, IO
• Fourth Superior Oblique
• Sixth Lateral Rectus

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Anatomy Of The EOMs
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• Anatomy
• Why we treat
• Examination
• Esotropia
• Exotropia
• Syndromes

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Why We Treat

• 1- Restore Stereopsis
• 2- Prevent Amblyopia
• 3- Prevent Confusion and Diplopia
• 4- Appearance

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Why We Treat

• 1- Restore Stereopsis
• Three dimensional vision..

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Why We Treat

• 2- Amblyopia
• Amblyopia is the unilateral or bilateral decrease
  of
• Vision caused by form vision deprivation and/or
• abnormal binocular interaction for which there is
  
• no obvious cause found by physical examination
• of the eye.

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Why We Treat

• The main types of Amblyopia are
• 1. Strabismic amblyopia results from abnormal
• binocular interaction where there is continued
• monocular suppression of the deviating eye. It is
  
• Characterized by an impairment of vision which is
  
• present even when the eye is forced to fixate.

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Why We Treat

• 2. Anisometropic amblyopia is caused by a
• difference in refractive error. It results from
• abnormal binocular interaction from the
• superimposition of a focused and unfocused image
• or from the superimposition of large and small
• images from aniseikonia.
• 3. Deprivation Amblyopia is caused from form
• vision deprivation of one eye.

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Why We Treat

• 3- Confusion and Diplopia
• DEFINITIONS
• 1. Visual axis is a line that passes through the
  point of fixation and the fovea. The normal
  visual axes intersect at the point of fixation.
• 2. Strabismus is a malalignment of the visual
  axes which, initially, results in confusion and
  diplopia.
• 3. Confusion is the simultaneous appreciation of
  two superimposed but dissimilar images caused by
  stimulation of corresponding points (usually
  foveae) by images of different objects.
• 4. Diplopia is the simultaneous appreciation of
  two images of one object. Jt results from a
  failure to maintain binocular vision.

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Why We Treat

• 4- Appearance

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• Anatomy
• Why we treat
• Examination
• Esotropia
• Exotropia
• Syndromes

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Strabismus
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Cover Uncover test Orthophoria, normal No
complaints, asymptomatic
G.Vicente,MD
G.Vicente,MD
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Cover Uncover test Esophoria, abnormal,
common Only seen when eye is covered Often
asymptomatic, no complaints Note OS does not move.
G.Vicente,MD
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Cover Uncover test Exophoria, abnormal,
common Only seen when eye is covered Note OS does
not move Often asymptomatic, no complaints.
G.Vicente,MD
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Alternate Cover test Exotropia, intermittent May
be visible with or without alternate cover May
have intermittent diplopia, especially when tired
or sick Mom sees misalignment every now and then.
G.Vicente,MD
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Alternate Cover test Exotropia, Constant May be
visible with or without alternate cover May or
may not have constant diplopia
G.Vicente,MD
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How much to operate
Alternate Cover test with Prism Exotropia,
Constant Use prism to quantitate the
deviation. Change prism power until movement is
neutralized. Use this number to plan surgery
G.Vicente,MD
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• Anatomy
• Why we treat
• Examination
• Esotropia
• Exotropia
• Syndromes

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Esotropia

• Inward deviation of the eyes
• Classification of Esotropia
• Comitant or incomitant.
• Accommodative or non-accommodative

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Esotropia

• ACCOMMODATIVE ESOTROPIA
• 1. Refractive
• . fully accommodative
• . partially accommodative
• 2. Non-refractive
• . with convergence excess
• . with accommodation weakness

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Esotropia

• NON-ACCOMMODATIVE ESOTROPIA
• . Infantile
• . microtropia
• . basic
• . convergence excess
• . convergence spasm
• . divergence insufficiency
• . divergence paralysis
• . sensory
• . consecutive
• . acute-onset
• . cyclic

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Refractive Accommodative Esotropia

• Refractive accommodative esotropia, with a normal
  
• AC/A ratio, is a physiological response to
  excessive
• hypermetropia and is beyond the patient's
  fusional
• divergence amplitude.
• The deviation presents at about the age of 2.5
  years, with
• a range of 6 months to 7 years. The two types
  are
• 1. Fully accommodative, which is completely
  eliminated by correction of the hypermetropic
  refractive error
• 2. Partially accommodative, which is only
  partially eliminated by correction of
  hypermetropia

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Refractive Accommodative Esotropia

• MANAGEMENT
• 1.Refraction is performed and any significant
  error corrected. In
• children under the age of 6 years, the full
  cycloplegic refraction
• should be prescribed. In the fully accommodative
  refractive
• esotrope this will control the deviation for both
  near and distance.
• 2. Bifocals may be prescribed if there is
  accommodative esotropia
• for near. The purpose of bifocals is to allow the
  child to maintain
• fusion at near. The ultimate prognosis for
  complete withdrawal of
• spectacles is related to the degree of
  hypermetropia, the amount of
• associated astigmatism and also the AC/A ratio.
  In some cases the
• spectacles need to be worn only for close work.

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Refractive Accommodative Esotropia

• 3. Surgery should be considered if spectacles do
  not fully correct the deviation and after every
  attempt has been made to treat amblyopia. The two
  main surgical options are
• (a) Recession-resection on the amblyopic eye in
  patients with residual amblyopia.
• (b) Bilateral medial rectus recessions in
  patients with equal vision in both eyes.

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Refractive Accommodative Esotropia
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Infantile Esotropia

• Infantile (Congenital) Esotropia
• CLINICAL FEATURES
• Infantile Esotropia is defined as Esotropia
• developing within the first 6 months of birth in
  an
• otherwise normal infant.

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Infantile Esotropia

• 1. Signs
• (a) The angle is usually fairly large (gt30) and
  stable.
• (b) Fixation in most infants is alternating in
  the primary
• position and crossfixating in side gaze, so that
  the child
• uses the right eye in left gaze and the left eye
  in right gaze.
• This pattern of crossed fixation will give the
  false
• impression of abduction deficit with a bilateral
  sixth nerve
• palsy. However, abduction can usually be
  demonstrated
• by either using the doll's head manoeuvre or
  rotating the
• child.

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Infantile Esotropia

• (c) Nystagmus, if present, is usually horizontal
  although it may be latent.
• (d) The refractive error is usually normal for
  the age of the child (about 1.50 D).
• (e) Inferior oblique overactions may be present
  initially or develop later.
• (f) Poor potential for BSV.

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Infantile Esotropia

• 2. Differential diagnosis
• (a) Congenital sixth nerve palsy.
• (b) Sensory Esotropia due to organic eye disease.
• (c) Nystagmus blockage syndrome in which
  Esotropia dampens a horizontal nystagmus.
• (d) Duane syndrome types I and III.
• (e) Mobius syndrome.
• (f) Strabismus fixus.

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Infantile Esotropia

• MANAGEMENT
• Initial management. Ideally, the eyes should be
  aligned at the very
• latest by the age of 2 years. This usually means
  performing the
• initial surgery before the age of 12 months, but
  only after amblyopia
• has been corrected. The initial procedure is
  recession of both
• medial recti. Any associated overactions of the
  inferior obliques
• should also be treated. An acceptable goal is
  alignment of the eyes
• to within 10 PD, associated with peripheral
  fusion and central
• suppression. This small-angle residual strabismus
  is compatible with
• a stable outcome even if bifoveal fusion is not
  achieved.

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Infantile Esotropia
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Infantile Esotropia
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Infantile Esotropia
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• Anatomy
• Why we treat
• Examination
• Esotropia
• Exotropia
• Syndromes

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Strabismus
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Exotropia

• Classification
• 1. Constant
• . Congenital
• . Sensory
• . Consecutive
• 2. Intermittent
• . divergence excess (worse for distance)
• . convergence weakness (worse for near)
• . basic exotropia (same for distance and near)

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Constant Exotropia

• CONGENITAL EXOTROPIA
• 1. Presentation is at birth, in contrast to
  infantile esotropia.
• 2. Signs
• (a) Normal refraction.
• (b) Large and constant angle.
• (c) DVD may be present.
• 3. Treatment is mainly surgical.

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Constant Exotropia

• OTHER TYPES
• 1. Sensory Exotropia, which is the result of
  disruption of binocular reflexes by acquired
  lesions, such as cataract or other opacities of
  the media, in children over the age of 5 years or
  in adults. If possible, treatment consists of
  correction of amblyopia followed by surgery.
• 2. Consecutve exotropia which most frequently
  follows previous correction or overcorrection of
  an esodeviation

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Intermittent Exotropia

• Presentation is most frequent at around 2 years.
• The Exotropia may be precipitated by bright light
  
• (resulting in reflex closure of the affected
  eye),
• day-dreaming, fatigue, ill health or visual
• distraction. Occasionally, the deviation remains
• constant and very rarely it may decrease.

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Intermittent Exotropia

• MANAGEMENT
• 1. Spectacle correction in myopic patients may,
  in some
• cases, control the deviation.
• 2. Orthoptic treatment consisting of occlusion
  therapy,
• diplopia awareness, and improvement of fusional
• convergence, may also be useful in selected
  cases.
• 3. Surgery is necessary in most patients by about
  the age
• of 5 years.

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Intermittent Exotropia
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• Anatomy
• Why we treat
• Examination
• Esotropia
• Exotropia
• Syndromes

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Syndromes

• Duane Syndrome
• Brown Syndrome

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Duane Syndrome

• The hallmark of Duane syndrome is retraction of
• the globe on attempted adduction caused by co-
• contraction of the medial and lateral recti. Both
  
• eyes are affected in about 20 of cases. Some
• children with Duane syndrome have associated
• congenital defects the most common is perceptive
  
• deafness with associated speech disorder.

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Duane Syndrome

• CLASSIFICATION
• 1. Type I, the most common, is characterized by
• . Limited or absence of abduction.
• . Normal or mildly limited adduction.
• . In the primary position, straight or slightly
  esotropic.
• 2. Type II, the least common, is characterized
  by
• . Limited adduction.
• . Normal or mildly limited abduction.
• . In primary position, straight or slightly
  exotropic.
• 3. Type III, is characterized by
• . Limited adduction and abduction.
• . In the primary position, straight or slightly
  esotropic.

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Duane Syndrome

• Other features, which may occur in each of the
  subgroups, are the following
• (a) On attempted adduction there is retraction of
  the globe and narrowing of the palpebral fissure,
  produced by the co-contraction of the medial and
  lateral recti of the involved eye.
• (b) On attempted abduction, the palpebral fissure
  opens and the globe assumes its normal position.
• (c) An up-shoot or down-shoot in adduction is
  seen in some patients. It has been suggested that
  this is a 'bridle' or 'leash' phenomenon,
  produced by a tight lateral rectus muscle which
  slips over or under the globe and produces an
  anomalous vertical movement of the eye.

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Duane Syndrome
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Duane Syndrome

• Management
• In most cases the eyes are straight in the
  primary position and there
• is no amblyopia. Surgery is indicated if the eyes
  are not straight in
• the primary position and the patient has to adopt
  an abnormal head
• posture to achieve fusion.
• Surgery may also be necessary for cosmetically
  unacceptable up-
• shoots, down-shoots or severe retraction.
• Amblyopia, when present, is usually the result of
  anisometropia and
• not strabismus.

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Brown Syndrome

• CLINICAL FEATURES
• 1. Major signs of a right Brown syndrome are
• (a) Usually straight in the primary position.
• (b) Limited right elevation in adduction and
  occasionally also in the primary position.
• (c) Usually normal right elevation in abduction.
• (d) No or minimal superior oblique overaction.
• (e) Positive forced duction test on elevating the
  globe in adduction.

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Brown Syndrome
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Brown Syndrome

• 2. Variable signs
• (a) Downshoot in adduction.
• (b) Hypotropia in primary position.
• (c) Anomalous head position with ipsilateral head
  tilt and chin up.

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Brown Syndrome

• CAUSES
• Brown syndrome is usually congenital but
  occasionally may be acquired
• 1. Congenital
• (a) Idiopathic.
• (b) Congenital click syndrome where there is
  impaired movement of the tendon through the
  trochlea.
• 2. Acquired
• (a) Iatrogenic damage of the trochlea or superios
  oblique tendon.
• (b) Inflammation of the tendon which may be
  caused by rheumatoid arthritis, pansinusitis and
  scleritis.

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Brown Syndrome

• Management
• 1. Congenital cases do not usually require
  treatment. Indications for surgery include the
  presence of a primary position hypotropia and/or
  an anomalous head posture.
• 2. Acquired cases may benefit from steroids.

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Strabismus

• Refer to an Ophthalmologist.
• Talk to the parents.
• AMBLYOPIA
• Normal Visual function (Streopsis)

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Strabismus

• Treatment
• Should be started as early as possible
• Glasses
• Surgery
• (Botox Injections)

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