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STRABISMUS: IS IT ‘STRABISMIC’ ?
…. NEUROLOGICAL?OR BOTH?
STRABISMUS: IS IT ‘STRABISMIC’ ?
…. NEUROLOGICAL?OR BOTH?
LIONEL KOWALDIRECTOR, OCULAR MOTILITY CLINIC, RVEEH
SENIOR CLINICAL FELLOW, DEPT OPHTHALMOLOGY, UNIVERSITY OF MELBOURNE
FIRST VICE PRESIDENT, INTERNATIONAL STRABISMOLOGICAL ASSOCIATION, 2002-2010
LIONEL KOWALDIRECTOR, OCULAR MOTILITY CLINIC, RVEEH
SENIOR CLINICAL FELLOW, DEPT OPHTHALMOLOGY, UNIVERSITY OF MELBOURNE
FIRST VICE PRESIDENT, INTERNATIONAL STRABISMOLOGICAL ASSOCIATION, 2002-2010
OVERVIEW….OVERVIEW….
OF THE CAUSES, ASSOCIATIONS AND TYPES OF STRABISMUS
IDENTIFYING SOME COMMON / UNDER- RECOGNISED ASSOCIATIONS
OF THE CAUSES, ASSOCIATIONS AND TYPES OF STRABISMUS
IDENTIFYING SOME COMMON / UNDER- RECOGNISED ASSOCIATIONS
STRABISMUSSTRABISMUS
Any ocular misalignment
INCLUDES:Abnormalities of development of acuity Abnormalities of development of binocularity The variants of congenital nystagmus
Any ocular misalignment
INCLUDES:Abnormalities of development of acuity Abnormalities of development of binocularity The variants of congenital nystagmus
CHILDHOOD STRABISMUSCHILDHOOD STRABISMUS
1. Derive largely from refractive disorders
2. Pure neurological3. Derive largely from abnormal early visual devpt
4. Special types
1. Derive largely from refractive disorders
2. Pure neurological3. Derive largely from abnormal early visual devpt
4. Special types
STRABISMUS: END RESULT OF A COMPLEX JIGSAW
PUZZLE
STRABISMUS: END RESULT OF A COMPLEX JIGSAW
PUZZLE
Abnormalities in one / more of…Sensory developmentRefractionOrbital anatomyEOM anatomy / physiologyCortical / supranuclearAccommodation / convergenceeither cause or are caused by strabismus
Abnormalities in one / more of…Sensory developmentRefractionOrbital anatomyEOM anatomy / physiologyCortical / supranuclearAccommodation / convergenceeither cause or are caused by strabismus
COMPLEX JIGSAW PUZZLEAbnormal Sensory
development
COMPLEX JIGSAW PUZZLEAbnormal Sensory
development
AmblyopiaSuppressionAbnormal retinal correspondence
AmblyopiaSuppressionAbnormal retinal correspondence
COMPLEX JIGSAW PUZZLEAbnormal Refraction
COMPLEX JIGSAW PUZZLEAbnormal Refraction
Hyperopia or ‘plus’ error *Causes esotropia
Any asymmetric refractive errorCauses amblyopia, esotropia if +
*so-called ‘long sighted’ - NOT the mirror image of short sighted. The patient can see clearly by generating focusing effort = accommodation
Hyperopia or ‘plus’ error *Causes esotropia
Any asymmetric refractive errorCauses amblyopia, esotropia if +
*so-called ‘long sighted’ - NOT the mirror image of short sighted. The patient can see clearly by generating focusing effort = accommodation
COMPLEX JIGSAW PUZZLEAbnormal orbital
anatomy1
COMPLEX JIGSAW PUZZLEAbnormal orbital
anatomy1Orbital pulley heterotopyChanges muscle actionsGlobe size distorting muscle cone
Causes pseudo- 6thShallow / deep orbit Shallow: more prone to exotropia
Orbital pulley heterotopyChanges muscle actionsGlobe size distorting muscle cone
Causes pseudo- 6thShallow / deep orbit Shallow: more prone to exotropia
COMPLEX JIGSAW PUZZLEAbnormal orbital anatomy
2
COMPLEX JIGSAW PUZZLEAbnormal orbital anatomy
2
Intorted / extorted orbitMore prone to alphabet patterns
PlagiocephalyMore prone to oblique dysfunction
Intorted / extorted orbitMore prone to alphabet patterns
PlagiocephalyMore prone to oblique dysfunction
COMPLEX JIGSAW PUZZLEAbnormal EOM
anatomy / physiology
COMPLEX JIGSAW PUZZLEAbnormal EOM
anatomy / physiologyOblique muscle dysfunctionAbnormal elevation / depression in AB- or AD- duction
Globe torsion
Abnormal innervation [Duane's, CFEOM]
Strange incomitant strabismus
Oblique muscle dysfunctionAbnormal elevation / depression in AB- or AD- duction
Globe torsion
Abnormal innervation [Duane's, CFEOM]
Strange incomitant strabismus
COMPLEX JIGSAW PUZZLEAbnormal cortical /
supranuclear substrate 1
COMPLEX JIGSAW PUZZLEAbnormal cortical /
supranuclear substrate 1
motor fusion oculomotor ‘shock absorber’ / ‘glue’ that tries to keep eyes straight
sensory fusionstereopsis Abnormal binocular columns
motor fusion oculomotor ‘shock absorber’ / ‘glue’ that tries to keep eyes straight
sensory fusionstereopsis Abnormal binocular columns
COMPLEX JIGSAW PUZZLEAbnormal cortical /
supranuclear substrate 2
COMPLEX JIGSAW PUZZLEAbnormal cortical /
supranuclear substrate 2
Abnormal interneuronsLatent Manifest Latent Nystagmus = LMLN = Fixation Maldevelopment N
Just about any cause / association of devptl delay
ChiariPVL
Abnormal interneuronsLatent Manifest Latent Nystagmus = LMLN = Fixation Maldevelopment N
Just about any cause / association of devptl delay
ChiariPVL
COMPLEX JIGSAW PUZZLEAbnormal Accom - Conv
relationship
COMPLEX JIGSAW PUZZLEAbnormal Accom - Conv
relationship
Accom too much convergence
Conv too much accommodation
*too little is rarely a problem
Accom too much convergence
Conv too much accommodation
*too little is rarely a problem
TYPES OF STRABISMUSTYPES OF STRABISMUS
1. Derives from refractive disorders
2. Pure neurological3. Derives from abn early visual devpt
4. Special types
1. Derives from refractive disorders
2. Pure neurological3. Derives from abn early visual devpt
4. Special types
NORMAL ACCOMMODATIONNORMAL ACCOMMODATION
Accommodation and convergence = Focus and Aim = Focus and Aim are very tightly linked
ACCOMMODATIVE / ‘OPTOMETRIC’ ESOTROPIA
ACCOMMODATIVE / ‘OPTOMETRIC’ ESOTROPIA
+4 : Abn degree of accommodation required to see clearly
Abn amount of accomm convergence is generated
competes against motor fusion [oculomotor shock absorber]
+4 : Abn degree of accommodation required to see clearly
Abn amount of accomm convergence is generated
competes against motor fusion [oculomotor shock absorber]
WHAT DOES +4 MEAN?WHAT DOES +4 MEAN?
For distance, generates same accommodation that ‘perfect’ person generates when looking 1/4 m away.
For distance fixation, eyes will tend to aim @ a point 25cm away
When looking @ an object 25cm away, eyes will aim @ a point 12 cm away
For distance, generates same accommodation that ‘perfect’ person generates when looking 1/4 m away.
For distance fixation, eyes will tend to aim @ a point 25cm away
When looking @ an object 25cm away, eyes will aim @ a point 12 cm away
ACCOMMODATIVE / ‘OPTOMETRIC’ ESOTROPIA
ACCOMMODATIVE / ‘OPTOMETRIC’ ESOTROPIA
Exactly the same can happen with low + and abnormal accomm - convergence relationship*
Many of these bifocals*many synonyms - convergence Xs, high AC/A ratio
Exactly the same can happen with low + and abnormal accomm - convergence relationship*
Many of these bifocals*many synonyms - convergence Xs, high AC/A ratio
Developing an esotropia…
Developing an esotropia…Prolonged accommodation tendency to
inappropriate convergence and increased tone in medial recti
Increased tone will eventually exceed motor fusional reserve and esotropia!
Initially reversible with glassesEventually the medial rectus shortens so much that only botox or surgery will work
Glasses still required to prevent recurrence [and, when older, for clear vision]
Prolonged accommodation tendency to inappropriate convergence and increased tone in medial recti
Increased tone will eventually exceed motor fusional reserve and esotropia!
Initially reversible with glassesEventually the medial rectus shortens so much that only botox or surgery will work
Glasses still required to prevent recurrence [and, when older, for clear vision]
Accommodative esotropia
Accommodative esotropia
Usually 2-5 yrs oldUsually high + [thick magnifying lenses]
Sometimes low / normal + with abnormal relation b/w accomm and convergence
Background of normal visual devpt in first 6mo of life
Usually 2-5 yrs oldUsually high + [thick magnifying lenses]
Sometimes low / normal + with abnormal relation b/w accomm and convergence
Background of normal visual devpt in first 6mo of life
Developing an esotropia…
Developing an esotropia…
Happens more readily * if motor fusion is impaired:
chromosomal defect / devptl delay
AmblyopiaOrbital anomalyLMLN
* younger, lower +
Happens more readily * if motor fusion is impaired:
chromosomal defect / devptl delay
AmblyopiaOrbital anomalyLMLN
* younger, lower +
‘Breakdown of pre- existing phoria…’‘Breakdown of pre- existing phoria…’
Only acceptable as a presumptive label if:
Wears thick magnifying lenses± amblyopiaAccomm disturbed e.g. Ditropan
Only acceptable as a presumptive label if:
Wears thick magnifying lenses± amblyopiaAccomm disturbed e.g. Ditropan
TYPES OF STRABISMUSTYPES OF STRABISMUS
1. Derives from refractive disorders
2. Pure neurological
3. Derives from abn early visual devpt
4. Special types
1. Derives from refractive disorders
2. Pure neurological
3. Derives from abn early visual devpt
4. Special types
‘Pure’ neurological strabismus‘Pure’ neurological strabismus
True cong sup obl palsy
6th
CFEOM [hypoplasia sup div 3rd; KIF mutation]
..have 2ary effects that are dependent on age of onset and associated factors such as refraction
True cong sup obl palsy
6th
CFEOM [hypoplasia sup div 3rd; KIF mutation]
..have 2ary effects that are dependent on age of onset and associated factors such as refraction
R SOP
HEAD TILT TO LEFT
R IO OA
R SO UA
TIGHT RSR RIR ‘UA’
True sup obl palsyTrue sup obl palsy
LSO OK RSO ?absent
REAL CONG R SOP & CONG ET FIXING WITH PARETIC R EYE
R SO atrophicR SO atrophic
Fake SOPConditions that simulate
SOPFalse +ve diagnostic rate ?50%
Fake SOPConditions that simulate
SOPFalse +ve diagnostic rate ?50%
Abnormal cyclovertical anatomyCraniofacial anomalies Posteroplaced trochlea [Bagolini]Fink : 20% of SO and IO have > 30 degrees asymmetry in course
Demer: orbital pulley displacements
Abnormal physiologyBrodsky’s wild pitch
Abnormal cyclovertical anatomyCraniofacial anomalies Posteroplaced trochlea [Bagolini]Fink : 20% of SO and IO have > 30 degrees asymmetry in course
Demer: orbital pulley displacements
Abnormal physiologyBrodsky’s wild pitch
TYPES OF STRABISMUSTYPES OF STRABISMUS
1. Derives from refractive disorders
2. Pure neurological
3. Derives from abnormal early visual development
4. Special types
1. Derives from refractive disorders
2. Pure neurological
3. Derives from abnormal early visual development
4. Special types
1. Abnormal symmetric acuity devpt ‘Congenital
Nystagmus’ * = CN
1. Abnormal symmetric acuity devpt ‘Congenital
Nystagmus’ * = CN
Bilateral bad refractive errorAlbinism : optic n dysplasia, foveal hypoplasia
Bil optic n hypoplasiaBil cataractsCN degrades vision further
* aka Idiopathic Infantile N, Cong motor N, Cong Sensory N,…
Bilateral bad refractive errorAlbinism : optic n dysplasia, foveal hypoplasia
Bil optic n hypoplasiaBil cataractsCN degrades vision further
* aka Idiopathic Infantile N, Cong motor N, Cong Sensory N,…
‘Congenital Nystagmus’ = CN
‘Congenital Nystagmus’ = CN
Pendular / jerkGreater on lateral gazeUNIQUE : CONVERGENCE NULLFace turnsPathognomonic waveform
Pendular / jerkGreater on lateral gazeUNIQUE : CONVERGENCE NULLFace turnsPathognomonic waveform
CN: face turn null & convergence null
CN: face turn null & convergence null
Null zone on R gazedrives face turn / tilt to L
N to L when L of nullN to R when R of null
Convergence null : unique to CN
Convergence null : unique to CN
QuickTime™ and aYUV420 codec decompressor
are needed to see this picture.
Abnormal binocularity devpt Latent Manifest Latent N *
Abnormal binocularity devpt Latent Manifest Latent N *
Caused by…Any strabismusAsymmetric refractionMonocular vision reducing pathology - cataract, optic n hypo,….
* aka Fixation Maldevelopment N
Caused by…Any strabismusAsymmetric refractionMonocular vision reducing pathology - cataract, optic n hypo,….
* aka Fixation Maldevelopment N
Abnormal binocularity devpt Latent Manifest Latent N Abnormal binocularity devpt Latent Manifest Latent N
JerkGreater on ABductionUNIQUE : Fast phase to fixing eye
Face turns : RF R face turn, LF L face turn
Head tilts : RF R tilt, LF L tilt
JerkGreater on ABductionUNIQUE : Fast phase to fixing eye
Face turns : RF R face turn, LF L face turn
Head tilts : RF R tilt, LF L tilt
LMLN LMLN
VIDEO OF POST OP LMLN; NOW ‘PURE’ LN
VIDEO OF POST OP LMLN; NOW ‘PURE’ LN
Esophoria after Exotropia surgeryN to fixing eye
LMLN : N fixing eye
LMLN : N fixing eye
QuickTime™ and aYUV420 codec decompressor
are needed to see this picture.
Fast phase to fixing eye
LMLNLMLN
COMMONLY CONGENITAL ESOTROPIA but can cause / be associated with other strabismus
Also CAUSES DISSOCIATED H & V DEVIATIONS
COMMONLY CONGENITAL ESOTROPIA but can cause / be associated with other strabismus
Also CAUSES DISSOCIATED H & V DEVIATIONS
CONGENITAL ESOTROPIACONGENITAL ESOTROPIA
ASSOCIATIONS OF LMLN & Congenital ET
ASSOCIATIONS OF LMLN & Congenital ET
Down’s 30%Severe neonatal course IVH /HC
near 100%PVL
Down’s 30%Severe neonatal course IVH /HC
near 100%PVL
VERTICALS IN CONG STRAB : DVD
Dissociated Vertical Deviation
VERTICALS IN CONG STRAB : DVD
Dissociated Vertical Deviation
Common pattern:Right fixation: LL fixation: R
Contralateral DVD is the end result of ‘braking’ the torsional component of LMLN in the fixing eye to try and improve acuity
Common pattern:Right fixation: LL fixation: R
Contralateral DVD is the end result of ‘braking’ the torsional component of LMLN in the fixing eye to try and improve acuity
VERTICALS IN CET : DVD
VERTICALS IN CET : DVD
RE fixing LE
CONGENITAL STRABISMUSCONGENITAL STRABISMUS
Head turns / face tilts are common
Caused by attempts to minimise blur effect of the LMLN
Head turns / face tilts are common
Caused by attempts to minimise blur effect of the LMLN
Alternating Face TurnAlternating Face Turn
L Fixation : L Face TurnR Fixation : R Face Turn
Ciancia’s syndrome: preference for fixation in adduction because recruiting medial rectus ‘brakes’ horizontal component of LMLN improved vision
L Fixation : L Face TurnR Fixation : R Face Turn
Ciancia’s syndrome: preference for fixation in adduction because recruiting medial rectus ‘brakes’ horizontal component of LMLN improved vision
Special case:Head tilt to fixing eye
Special case:Head tilt to fixing eye
LF drives HT to LRF : no HT
Caused by Torsional LMLN
LF drives HT to LRF : no HT
Caused by Torsional LMLN
LF drives HT to LTorsional LMLNLF drives HT to LTorsional LMLN
LMLN is the cong nystag seen with disorders of binocular development
[?always] Seen in cong ET= Fixation Maldevelopment N. Usually has H component, sometimes T as well
Fine torsional N on slit lamp
N degrades vision - vision improves when N blocked
LMLN is the cong nystag seen with disorders of binocular development
[?always] Seen in cong ET= Fixation Maldevelopment N. Usually has H component, sometimes T as well
Fine torsional N on slit lamp
N degrades vision - vision improves when N blocked
Special case:Alternating Head TiltSpecial case:Alternating Head Tilt
LF drives L tiltRF drives R tilt
= Ciancia’s syndrome
LF drives L tiltRF drives R tilt
= Ciancia’s syndrome
Recap…Abnormal binocularity devpt Latent Manifest Latent
N
Recap…Abnormal binocularity devpt Latent Manifest Latent
N
Features of this type of strab recognised by the accompaniments.
LMLN, + one/ more of…Head tilt / face turn to fixing eye
DVDsLarge angle esotropia
Features of this type of strab recognised by the accompaniments.
LMLN, + one/ more of…Head tilt / face turn to fixing eye
DVDsLarge angle esotropia
‘Ophthalmic’ PVL‘Ophthalmic’ PVL
Optic n hypoplasia uni-/bi-Cognitive visual problems -
normal acuityReduced acuityLMLNCN
Optic n hypoplasia uni-/bi-Cognitive visual problems -
normal acuityReduced acuityLMLNCN
THINGS THAT LOOK LIKE ‘STRABISMIC’ STRABISMUSTHINGS THAT LOOK LIKE
‘STRABISMIC’ STRABISMUS
CHIARI – later onset
‘deterioration of old latent strabismus ‘ – there always has to be a credible background / predisposition. And a reason for breakdown
CHIARI – later onset
‘deterioration of old latent strabismus ‘ – there always has to be a credible background / predisposition. And a reason for breakdown
THINGS THAT LOOK LIKE ‘STRABISMIC’ STRABISMUSTHINGS THAT LOOK LIKE
‘STRABISMIC’ STRABISMUS
Autoimmune neuropathies
Myesthenia
Autoimmune neuropathies
Myesthenia
Strabismus syndromesStrabismus syndromes
Duane’s
Brown’s
Duane’s
Brown’s
Brown’sBrown’sTight superior oblique tendon
Restricted elevation in aDuction
Duane’sRetraction on
adduction
Duane’sRetraction on
adductionRetraction R on L gazeRestricted aDduction RRestricted aBduction L
Co-firing Lateral rectus on aDuction
Duane’sDuane’s
Retraction L on R gazeRestricted aDduction L
Co-firing lateral rectus on aDuction
THANK YOUTHANK YOU