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extraocular motility
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Extraocular MotilityExtraocular Motility
Walter Huang, ODWalter Huang, OD
Yuanpei UniversityYuanpei University
Department of OptometryDepartment of Optometry
Extraocular MusclesExtraocular Muscles
PurposePurpose To control the movement of the globeTo control the movement of the globe
Extraocular MusclesExtraocular Muscles
Rectus musclesRectus muscles Superior rectus muscle (SR)Superior rectus muscle (SR) Inferior rectus muscle (IR)Inferior rectus muscle (IR) Medial rectus muscle (MR)Medial rectus muscle (MR) Lateral rectus muscle (LR)Lateral rectus muscle (LR)
Oblique musclesOblique muscles Superior oblique muscle Superior oblique muscle
(SO)(SO) Inferior oblique muscle (IO)Inferior oblique muscle (IO)
Anterior View of Right EyeAnterior View of Right Eye
Superior View of Right OrbitSuperior View of Right Orbit
Action of muscles affected by globe Action of muscles affected by globe position in the ocular orbit and muscle position in the ocular orbit and muscle orientationsorientations
Posterior View of Right EyePosterior View of Right Eye
Medial RectusMedial Rectus
Along the medial aspect of the eyeball, the Along the medial aspect of the eyeball, the medial rectus muscle inserts at a point medial rectus muscle inserts at a point 5.5mm of the limbus5.5mm of the limbus
It is controlled by the oculomotor nerve It is controlled by the oculomotor nerve (cranial nerve III)(cranial nerve III)
Contraction of this muscle causes Contraction of this muscle causes adadduction of the eyeduction of the eye
Medial RectusMedial Rectus
AdAdductionduction
Lateral RectusLateral Rectus
Along the lateral aspect of the eyeball, the Along the lateral aspect of the eyeball, the lateral rectus muscle inserts at a point lateral rectus muscle inserts at a point 7.0mm of the limbus7.0mm of the limbus
It is controlled by the abducens nerve It is controlled by the abducens nerve (cranial nerve VI)(cranial nerve VI)
Contraction of this muscle causes Contraction of this muscle causes ababduction of the eyeduction of the eye
Lateral RectusLateral Rectus
AbAbductionduction
Inferior RectusInferior Rectus
Along the inferior aspect of the eyeball, the Along the inferior aspect of the eyeball, the inferior rectus muscle inserts at a point inferior rectus muscle inserts at a point 6.5mm of the limbus6.5mm of the limbus
It is controlled by the oculomotor nerve It is controlled by the oculomotor nerve (cranial nerve III)(cranial nerve III)
Inferior RectusInferior Rectus
When the eyeball is positioned 23 degrees When the eyeball is positioned 23 degrees outward in the orbit with respect to primary outward in the orbit with respect to primary gaze, contraction of this muscle causes gaze, contraction of this muscle causes depression of the eyedepression of the eye
When the eyeball is positioned 67 degrees When the eyeball is positioned 67 degrees inward in the orbit with respect to primary inward in the orbit with respect to primary gaze, contraction of this muscle causes gaze, contraction of this muscle causes excycloduction of the eyeexcycloduction of the eye
Inferior RectusInferior Rectus
When the eyeball is positioned straight When the eyeball is positioned straight ahead in the orbit with respect to primary ahead in the orbit with respect to primary gaze, contraction of this muscle causes gaze, contraction of this muscle causes adadduction of the eyeduction of the eye
Contraction of this muscle causes Contraction of this muscle causes depression, excycloduction, and depression, excycloduction, and adadduction duction of the eyeof the eye
Position of IR and SRPosition of IR and SR
Primary Action of IRPrimary Action of IR
DepressionDepression
Secondary Action of IRSecondary Action of IR
ExcycloductionExcycloduction
Tertiary Action of IRTertiary Action of IR
AdAdductionduction
Superior RectusSuperior Rectus
Along the superior aspect of the eyeball, Along the superior aspect of the eyeball, the superior rectus muscle inserts at a the superior rectus muscle inserts at a point 7.5mm of the limbuspoint 7.5mm of the limbus
It is controlled by the oculomotor nerve It is controlled by the oculomotor nerve (cranial nerve III)(cranial nerve III)
Superior RectusSuperior Rectus
When the eyeball is positioned 23 degrees When the eyeball is positioned 23 degrees outward in the orbit with respect to primary outward in the orbit with respect to primary gaze, contraction of this muscle causes gaze, contraction of this muscle causes elevation of the eyeelevation of the eye
When the eyeball is positioned 67 degrees When the eyeball is positioned 67 degrees inward in the orbit with respect to primary inward in the orbit with respect to primary gaze, contraction of this muscle causes gaze, contraction of this muscle causes incycloduction of the eyeincycloduction of the eye
Superior RectusSuperior Rectus
When the eyeball is positioned straight When the eyeball is positioned straight ahead in the orbit with respect to the ahead in the orbit with respect to the primary gaze, contraction of this muscle primary gaze, contraction of this muscle causes causes adadduction of the eyeduction of the eye
Contraction of this muscle causes Contraction of this muscle causes elevation, incycloduction, and elevation, incycloduction, and adadduction of duction of the eyethe eye
Primary Action of SRPrimary Action of SR
ElevationElevation
Secondary Action of SRSecondary Action of SR
IncycloductionIncycloduction
Tertiary Action of SRTertiary Action of SR
AdAdductionduction
Superior ObliqueSuperior Oblique
The superior oblique muscle passes The superior oblique muscle passes through the trochlea and its insertion on through the trochlea and its insertion on the eyeball below the superior rectus the eyeball below the superior rectus muscle is at 51 degrees with respect to muscle is at 51 degrees with respect to primary gazeprimary gaze
It is controlled by the trochlear nerve It is controlled by the trochlear nerve (cranial nerve IV)(cranial nerve IV)
Superior ObliqueSuperior Oblique
When the eyeball is positioned 39 degrees When the eyeball is positioned 39 degrees outward in the orbit with respect to primary outward in the orbit with respect to primary gaze, contraction of this muscle causes gaze, contraction of this muscle causes incycloduction of the eyeincycloduction of the eye
When the eyeball is positioned 51 degrees When the eyeball is positioned 51 degrees inward in the orbit with respect to primary inward in the orbit with respect to primary gaze, contraction of this muscle causes gaze, contraction of this muscle causes depression of the eyedepression of the eye
Superior ObliqueSuperior Oblique
When the eyeball is positioned straight When the eyeball is positioned straight ahead in the orbit with respect to the ahead in the orbit with respect to the primary gaze, contraction of this muscle primary gaze, contraction of this muscle causes causes ababductionduction
Contraction of this muscle causes Contraction of this muscle causes incycloduction, depression, and incycloduction, depression, and ababduction duction of the eyeof the eye
Position of SO and IOPosition of SO and IO
Primary Action of SOPrimary Action of SO
IncycloductionIncycloduction
Secondary Action of SOSecondary Action of SO
DepressionDepression
Tertiary Action of SOTertiary Action of SO
AbAbductionduction
Inferior ObliqueInferior Oblique
The insertion of the inferior oblique muscle The insertion of the inferior oblique muscle is on the eyeball below the lateral rectus is on the eyeball below the lateral rectus muscle at 51 degrees with respect to muscle at 51 degrees with respect to primary gazeprimary gaze
It is controlled by the oculomotor nerve It is controlled by the oculomotor nerve (cranial nerve III)(cranial nerve III)
Inferior ObliqueInferior Oblique
When the eyeball is positioned 39 degrees When the eyeball is positioned 39 degrees outward in the orbit with respect to primary outward in the orbit with respect to primary gaze, contraction of this muscle causes gaze, contraction of this muscle causes excycloduction of the eyeexcycloduction of the eye
When the eyeball is positioned 51 degrees When the eyeball is positioned 51 degrees inward in the orbit with respect to primary inward in the orbit with respect to primary gaze, contraction of this muscle causes gaze, contraction of this muscle causes elevation of the eyeelevation of the eye
Inferior ObliqueInferior Oblique
When the eyeball is positioned straight When the eyeball is positioned straight ahead in the orbit with respect to the ahead in the orbit with respect to the primary gaze, contraction of this muscle primary gaze, contraction of this muscle causes causes ababductionduction
Contraction of this muscle causes Contraction of this muscle causes excycloduction, elevation, and excycloduction, elevation, and ababduction duction of the eyeof the eye
Primary Action of IOPrimary Action of IO
ExcycloductionExcycloduction
Secondary Action of IOSecondary Action of IO
ElevationElevation
Tertiary Action of IOTertiary Action of IO
AbAbductionduction
Functions of Extraocular MusclesFunctions of Extraocular Muscles
MuscleMuscle Primary Primary ActionAction
Secondary Secondary ActionAction
Tertiary Tertiary ActionAction
MRMR AdductionAdduction
LRLR AbductionAbduction
IRIR DepressionDepression ExcycloExcyclo
ductionduction
AdductionAdduction
Functions of Extraocular MusclesFunctions of Extraocular Muscles
MuscleMuscle Primary Primary ActionAction
Secondary Secondary ActionAction
Tertiary Tertiary ActionAction
SRSR ElevationElevation IncycloIncyclo
ductionduction
AdductionAdduction
SOSO IncycloIncyclo
ductionduction
DepressionDepression AbductionAbduction
IOIO ExcycloExcyclo
ductionduction
ElevationElevation AbductionAbduction
TerminologyTerminology
Duction: describes movement of Duction: describes movement of oneone eye eye AbductionAbduction AdductionAdduction Supraduction or elevationSupraduction or elevation Infraduction or depressionInfraduction or depression Incycloduction or intorsionIncycloduction or intorsion Excycloduction or extorsionExcycloduction or extorsion
TerminologyTerminology
Version: describes movement of Version: describes movement of twotwo eyes eyes in the in the samesame direction direction DextroversionDextroversion LevoversionLevoversion SupraversionSupraversion InfraversionInfraversion
TerminologyTerminology
Vergence: describes movement of Vergence: describes movement of twotwo eyes in eyes in oppositeopposite directions directions ConvergenceConvergence DivergenceDivergence
Version and VergenceVersion and Vergence
Near Point of ConvergenceNear Point of Convergence
Maximum convergence ability or NPC is Maximum convergence ability or NPC is measured by as part of confrontational measured by as part of confrontational testingtestingNPC = point of intersection of line of sight NPC = point of intersection of line of sight when eyes are maximally convergedwhen eyes are maximally convergedTheoretically, NPC should be measured Theoretically, NPC should be measured from center of rotation of eyesfrom center of rotation of eyesClinically, NPC is measured from the facial Clinically, NPC is measured from the facial planeplane
Near Point of ConvergenceNear Point of Convergence
NPC break point (target becomes double) NPC break point (target becomes double) greater than 7cm is considered abnormalgreater than 7cm is considered abnormal
Average NPC is approximately 5cmAverage NPC is approximately 5cm
The recovery point (target becomes The recovery point (target becomes single) is expected to be within 10cmsingle) is expected to be within 10cm
Near Point of ConvergenceNear Point of Convergence
A patient with reduced NPCA patient with reduced NPC Convergence insufficiency Convergence insufficiency Some presbyopesSome presbyopes SymptomsSymptoms
Diplopia, frontal headache, asthenopia, fatigue, Diplopia, frontal headache, asthenopia, fatigue, and reduced reading abilityand reduced reading ability
The patient may benefit from vision therapy or The patient may benefit from vision therapy or prism in reading Rxprism in reading Rx
Object Tracking MovementsObject Tracking Movements
Saccade: fast, step-like eye movement (up Saccade: fast, step-like eye movement (up to 1000 deg/sec) that places image of the to 1000 deg/sec) that places image of the target on the foveatarget on the fovea ReadingReading Looking from point A to BLooking from point A to B Fixating on a stationary targetFixating on a stationary target
Object Tracking MovementsObject Tracking Movements
Pursuit: slow, smooth-following movement Pursuit: slow, smooth-following movement (up to 30 deg/sec) that maintains image of (up to 30 deg/sec) that maintains image of the target on the foveathe target on the fovea Following a moving targetFollowing a moving target
Extraocular Motility TestingExtraocular Motility Testing
The most common test for extraocular The most common test for extraocular motility is the broad H testmotility is the broad H test
EOM testing is also part of confrontational EOM testing is also part of confrontational testingtesting
Extraocular Motility TestingExtraocular Motility Testing
PurposePurpose To investigate the integrity of the extraocular To investigate the integrity of the extraocular
muscles and their nervesmuscles and their nerves To assess the patient’s ability to perform To assess the patient’s ability to perform
version eye movementsversion eye movements To determine if strabismus is comitant (i.e., To determine if strabismus is comitant (i.e.,
deviation does not change with direction of deviation does not change with direction of gaze)gaze)
Broad H TestBroad H Test
A pursuit test done binocularly with A pursuit test done binocularly with penlight at a test distance of 30 to 40cmpenlight at a test distance of 30 to 40cm
It tests 9 positions of action, starting with It tests 9 positions of action, starting with primary positionprimary position
Broad H TestBroad H Test
Broad H TestBroad H Test
It tests It tests fields of action fields of action of the 6 extraocular of the 6 extraocular musclesmuscles
Field of action = direction where a Field of action = direction where a particular muscle has the greatest actionparticular muscle has the greatest action
Broad H TestBroad H Test
Examples of fields of actionExamples of fields of action Right LR: field of action is the right-hand fieldRight LR: field of action is the right-hand field Right MR: field of action is the left-hand fieldRight MR: field of action is the left-hand field This is opposite for left LR and left MRThis is opposite for left LR and left MR
Position of SR and IRPosition of SR and IR
Action of SR and IRAction of SR and IR
SR and IR lie in a muscle plane that SR and IR lie in a muscle plane that makes a 23 degree angle with the straight makes a 23 degree angle with the straight ahead positionahead position
When the eye turns out 23 degrees, SR When the eye turns out 23 degrees, SR acts as a pure elevator, and IR acts as a acts as a pure elevator, and IR acts as a pure depressorpure depressor
Position of SO and IOPosition of SO and IO
Action of SO and IOAction of SO and IO
SO and IO lie in a muscle plane that SO and IO lie in a muscle plane that makes a 51 degree angle with the straight makes a 51 degree angle with the straight ahead directionahead direction
When the eye turns in 51 degrees, SO When the eye turns in 51 degrees, SO acts as a pure depressor, and IO acts as a acts as a pure depressor, and IO acts as a pure elevatorpure elevator
Broad H TestBroad H Test
It is not necessary to direct the patient’s It is not necessary to direct the patient’s gaze exactly 23 degrees or 51 degrees gaze exactly 23 degrees or 51 degrees during the broad H testduring the broad H test
40 degrees to the right or left is enough to 40 degrees to the right or left is enough to detect any limitation of movementdetect any limitation of movement
Muscles and their Fields of Muscles and their Fields of ActionAction
Right-hand elevator: muscle that turns the Right-hand elevator: muscle that turns the eye upward when the eye is already eye upward when the eye is already looking to the right (RSR and LIO)looking to the right (RSR and LIO)
Right-hand depressor: muscle that turns Right-hand depressor: muscle that turns the eye downward when the eye is already the eye downward when the eye is already looking to the right (RIR and LSO)looking to the right (RIR and LSO)
Muscles and their Fields of Muscles and their Fields of ActionAction
Left-hand elevator: muscle that turns the Left-hand elevator: muscle that turns the eye upward when the eye is already eye upward when the eye is already looking to the left (LSR and RIO)looking to the left (LSR and RIO)
Left-hand depressor: muscle that turns the Left-hand depressor: muscle that turns the eye downward when the eye is already eye downward when the eye is already looking to the left (LIR and RSO)looking to the left (LIR and RSO)
Muscles and their Fields of Muscles and their Fields of ActionAction
Example: A patient is asked to direct gaze Example: A patient is asked to direct gaze 23 degrees to the right and up, any 23 degrees to the right and up, any limitation in movement of OD is due to limitation in movement of OD is due to problem with RSRproblem with RSR
Muscles and Their Fields of ActionMuscles and Their Fields of Action
Broad H TestBroad H Test
Look for lags or overshoots at various Look for lags or overshoots at various diagnostic positions of gazediagnostic positions of gaze
Look for smooth and accurate pursuit Look for smooth and accurate pursuit movementsmovements
Look for any gaze restrictions or Look for any gaze restrictions or overactions of muscle in the 9 positionsoveractions of muscle in the 9 positions
Look for comitancyLook for comitancy
ComitancyComitancy
When deviation of the visual axes remains When deviation of the visual axes remains constant in all fields of gaze, there is constant in all fields of gaze, there is comitancycomitancy
When deviation of the visual axes changes When deviation of the visual axes changes with field of gaze, there is with field of gaze, there is noncomitancynoncomitancy
ComitancyComitancy
Check for comitancy by moving the target Check for comitancy by moving the target to different positions of gaze, while to different positions of gaze, while keeping the patient steadykeeping the patient steady
In general, a patient with EOM paresis is In general, a patient with EOM paresis is incomitantincomitant
Gaze RestrictionGaze Restriction
Overaction of MuscleOveraction of Muscle
Saccade TestSaccade Test
Test set-up is the same as for the broad H Test set-up is the same as for the broad H testtest
Direct patient to look quickly from positions Direct patient to look quickly from positions 8 to 2, and then back to 88 to 2, and then back to 8
Repeat rapid shifts of gaze from positions Repeat rapid shifts of gaze from positions 6 to 5, and then back to 66 to 5, and then back to 6
Look for accuracy of movement (i.e., Look for accuracy of movement (i.e., overshoots and undershoots)overshoots and undershoots)
Saccade TestSaccade Test
RecordingRecording
Expected FindingsExpected Findings
SAFESAFE SSmoothmooth AAccurateccurate FFullull EExtensivextensive