Basic Motility Examination
Alvina Pauline D. Santiago, MDPediatric Ophthalmology & Strabismus
Basic Course Lectures in Ophthalmology
Sentro Oftalmologico Jose Rizal
Philippine General Hospital 2014
Basic Strabismus Evaluation Chief complaint and History Vision assessment (with vision screening) Gross evaluation and slit lamp examination Refraction and need for cycloplegiaSensory and Motor examination
(Motility Examination) Dilated posterior pole evaluation
Sensory TestingPerform before any type of monocular
occlusion e.g., visual acuity testing, cover tests
must wear correctionmay need to correct deviationPrefer to do on a second visit
Sensory TestingNear stereoacuity
Fly vectograph/ Titmus Fly Test Lang stereotest Random dot stereograms
Distance stereoacuity Mentor BVAT AO vectograph Amblyoscope
Stereoacuity testsHorizontal disparityStimulate non-corresponding points Image disparity measured in sec of arc40-50 sec = central or bifoveal fixation80-3000 sec = peripheral fusion
Titmus fly test Monocular cues Need polarized glasses Image displacement
may be detected by alternate suppressors
Turn book 90 degrees, should be flat
Lang Stereoacuity test Random dot
stereogram No need for Polaroid
lenses Only for gross and
low grade stereopsis
Random dot stereogram 2 plates of randomly
displayed dots, one plate to each eye
Shape of figure displaced horizontally relative to other plate
No monocular cues Normal may fail
Distance Stereotest
Mentor BVAT System
Very good test for assessing control in X(T)
Red Green Distance Stereotest
Sensory TestingWorth 4 dot
near: tests peripheral fusion distance: tests central fusion
Retinal correspondence amblyoscope, Bagolini lenses
4 pd BO test: foveal suppression N: conjug sacc OU, slow recov in nonprism
eye
Worth Dot Test 2 green lights 1 red light 1 white light
Red-green glasses Usually red over
right eye At 1/3 m: W4D
separated by 6 degrees
At 6 m: 1.25 degrees
Amblyoscope or haploscope
AmblyoscopeMeasures fusional vergence amplitudesAngle of deviationArea of suppressionRetinal correspondenceTorsion Instrument convergence
Motor TestingOcular rotations Measuring the deviationAnomalous head posture
Ocular RotationsDuction: monocularVersion: binocularHering’s lawSherrington’s lawAlert to pattern deviations: e.g., A, VGrading scheme:
e.g., inferior oblique & superior oblique
Ocular RotationsCardinal gaze positions
RLR
LMR
RMR
LLR
RSR
LIO
RIR
LSO
RIO
LSR
RSO
LIR
Ocular Motility Evaluation
Ocular Motility Evaluation
RLR
LMR
RMR
LLR
RSR
LIO
RIR
LSO
RIO
LSR
RSO
LIR
(L) Inferior oblique dysfunction
+4 +1
-4 -1
(R) Superior oblique dysfunction
+4 +1
-4 -1
Motor TestingLight reflex testsCover testsOther tests
wear correction no prisms
Motor Testing: Light Reflex Tests
Bruckner testHirschberg light reflexKrimsky/modified Krimsky
Bruckner Test Ametropiastrabismus
Hirschberg’s Corneal Light Reflex
3.5 mm pupil: 15 degrees at pupil
edge 30 degrees between
limbus and edge of pupil
45 degrees at limbus 21 pd/mm
decentration
Krimsky vs Modified Krimsky
in front of deviating eye (modified Krimsky)
underestimates true angle
better at near
Motor Testing: Cover TestsPrimary gazeRight and left gazeUp and down gazeRight and left head tilt
Near: primary and down gaze
Cover TestsRequirements:
appropriate correction no prisms vs. prisms accommodative target distance:
6 m: 1/6 D of accommodation (approximates infinity)
> 6 m: X(T)
The Ideal TargetAbove threshold
e.g. Snellen acuity 20/20
present 20/50
The Ideal TargetWith sufficient detail and contourShould sustain interest
Toys as Targets One toy one look With detail May be coupled with
a light Sounds for tracking
but not vision testing
The Ideal TargetMaximum plus, least minus correctionAllows minimal accommodation at 6 mAccommodation exerted only 1/6 m,
considered zero for strabismus measurement purposes
Factors Affecting Measurement
Prism placement: plastic prisms:
frontal plane glass prisms:
prentice position
Stacking prisms Splitting prisms
Factors Affecting Measurement Method of testing:
Light reflex: Bruckner Hirschberg Krimsky/modified
Krimsky
Different cover tests Cover Test Alternate Cover Test
Factors Affecting MeasurementPatient factors:
accommodation and AC/A ratio axial length and globe size amblyopia and eccentric fixation refractive error and induced prisms
Cover Tests
Cover Uncover TestMust be performed before alternate
cover test Cover test: tropia Uncover test: phoria
also for fixation preference
Simultaneous Prism Cover Test
Tropia under binocular conditionsMonofixation syndrome
Estimate angle of deviation Present prism and cover simultaneously Absence of movement in tropic eye means
correcting prisms are accurate
Prism Under Cover TestFor Dissociated Vertical DeviationEvaluate one eye at a timePrism and cover presented to the same
eyeSeparate true hypertropia by using BU
prism neutralization in other eye
Techniques in Finding Strabismus
Bruckner test Spielmann
translucent occluder
Alternate Prism Cover TestPrisms before deviated eye
primary vs. secondary deviationUnless strabismic eye is preferred for
fixationEvaluates total deviation: manifest
(tropic) and latent (phoric)
Other TestsRed glass testMaddox rod
horizontal, vertical torsional
Parks 3-step test for isolated cyclovertical muscle palsy 3rd step is Bielschowsky maneuver
(L) Superior oblique palsy
Parks 3-step Test (LHT) I. Of 8 cyclovertical
muscles: 4 LSO, LIR, RSR, RIO
II. Of 4 cyclovertical muscles: 2 increase on R gaze:
LSO, RSR
III. Of 2 cyclovertical muscles: 1 increase of L tilt: LSO
Torsion EvaluationFunduscopyFundus photographyBlind spot mappingRed-Green Hess/Lee ScreenDouble Maddox RodsOblique (& Vertical) muscle dysfunction
Normal Optic Nerve Head-Fovea Angle Relationship
Direct Ophthalmoscope View:Fundus Torsion
Excyclorotation Incyclorotation
Inferior Oblique Overaction
PREOP POSTOP
Torsion Test: Double Maddox
Tests of Muscle FunctionForced duction testForce generation testSaccadic velocity analysisEMGDynamic MRI
Indications Incomitant deviationLimited ocular rotationDistinguish between restriction and
paresis/palsyDistinguish between paresis and palsy
Passive Forced Duction Some indications:
Trauma Endocrine Postoperative
restriction of motility Longstanding
deviation with secondary contracture
Congenital restrictions
Brown Duane
Transposition procedures
Orbital diseases Tumors Inflammation
AdvantagesHelp in deciding between treatment
optionsMonitor improvement of paretic mm
Tests of Muscle FunctionParesis vs. restriction
Forced duction test Force generation test Saccadic velocity analysis Differential intraocular pressure
EMG: ElectromyographyLimitations:
may record activity even if muscle still paretic
response suppressed by GA still used in some cases of Duane
syndrome and Botulinum injection
Passive Forced Duction Children > 7 yrs, adults Topical anesthetic +/-
Epinephrine Cover one eye: ensures
fixation Look as far as possible
in the direction of limited ocular rotation
Provide fixation target Watch out for “falling of
f” of eye
Passive Forced Duction “Can the forceps rotate the eye further
than the patient can using maximal innervation in that gaze field?”
Grasp limbus opposite the side of limited gaze Tenon’s and conj fused in one layer limits stretching/tearing of conj provides firm grasp
Passive Forced Duction
Follow natural arc of globeFor rectus muscles
Slight proptosis No retroplacement
Vertical rectus: 23 deg abductionResults:
cannot move globe further: restriction can move globe further: paresis
For Oblique Muscles: Retroplace globe Follow oblique muscle path
Guyton’s Oblique Traction Test “Stress Test” for obliques Retroplace globe Torsional movement
Passive Forced Duction
Oblique traction testing
Oblique traction testing
Oblique traction testing
Intraoperative Forced Duction TestingPerform routinely to feel “normal”Perform esp after resections
may be ortho in primary overcorrection in certain gazes
Perform after transpositions Intraoperative adjustable suturePerform after removing suspected
restrictions
Forced Duction ResultsAbsolute restriction
Graves, BrownUniform restriction
Scar tissue, muscle contractureLeash phenomenon
Scar tissue, long standing contracture
Pitfalls: Forced Duction Patient apprehension Errors in technique
“Falling off” Failure to proptose or retropulse globe
Succinylcholine (Anectine) Posterior restrictions Co-contractions Co-existing paresis and restriction
Active Force Generation Apply a
counteracting force Using the same
grasp on limbus Countertraction to
feel resistance WOF: corneal
abrasion, conj heme
Active Force GenerationDifferential IOPParesis vs. palsyCombined paresis and restriction
Results: Force GenerationNo force generated: PalsyWeak force generated: ParesisStrong force generated: RestrictionCommon pitfall: mild paresisCorrelate with saccadic velocity
analysis
FDT, FGT, Diagnosis
DIAGNOSIS DIAGNOSIS FDTFDT FGTFGT
Mech restrictionMech restriction restrictedrestricted normalnormal
Muscle palsyMuscle palsy freefree absentabsent
Paresis & restrictionParesis & restriction restrictedrestricted weakweak
Saccadic Velocity AnalysisStudy eye movement velocity
muscle activity return of muscle function
EOG techniques: problem-vertical InfraredScleral search coil
Office Saccadic Velocity Look at 2 separate
targets At least 20 deg movt
sufficient Compare
briskness of agonist and antagonist
with fellow eye Bring the eye where
muscle has maximum function full unrestricted motion
Pitfalls: Saccadic Velocity Errors in technique
failure to bring eye where muscle is still functioning
Pharmacologic Fatigue Time of day
Clinical Applications: SVParalytic StrabismusRestrictiveLost or slipped muscles Neurologic Disorders
MG: normal then weakens; use with Tensilon
PEO: general slowing INO: slowed adduction; normal abduction
Slowed Saccadic VelocitiesLR palsy abductionSO palsy downgazeMoebius horizontalMyasthenia normal then slowsSlipped/Lost reduced 20-50%
Magnetic Resonance Imaging
Cross-sectional areaApplications:
EOM palsy EOM heterotopy Severed/extirpated muscles Entrapment Mass
Normal coronal section
Laser vision ;-)
