7. Outcomes
• Enumerate requirements before performing sensory tests
• Perform correct near stereoacuity test
• Enumerate the different stereoacuity tests for distance and near
• Understand the basis of stereoacuity tests
• Understand the importance of sensory testing for strabismus
• Enumerate the indications for sensory testing
• Perform and interpret results of Worth 4-dot testing
• Know the indication and normal response for 4PD Base out test
• Be familiar with the amblyoscope and what it can assess
#BasicMotilityExam (c) APSantiago 20197
8. Sensory Testing
• Perform before any type of monocular occlusion
• e.g., visual acuity testing, cover tests
• Must wear correct prescription
• May need to correct deviation
• Prefer to do on a second visit
#BasicMotilityExam (c) APSantiago 20198
9. Sensory Testing
• Near stereoacuity
• Fly vectograph/ Titmus Fly Test
• Lang stereotest
• Random dot stereograms
• Distance stereoacuity
• Mentor BVAT
• AO vectograph
• Amblyoscope
#BasicMotilityExam (c) APSantiago 20199
10. Stereoacuity tests
• Horizontal disparity
• Stimulate non-corresponding points
• Image disparity measured in sec of arc
• 40-50 sec = central or bifoveal fixation
• 80-3000 sec = peripheral fusion
#BasicMotilityExam (c) APSantiago 201910
11. Titmus fly test
• Monocular cues
• Need polarized glasses
• Image displacement
may be detected by
alternate suppressors
• Turn book 90 degrees,
should be flat
From Rosenbaum & Santiago, ClinicalStrabismus Management
#BasicMotilityExam (c) APSantiago 201911
12. Lang Stereoacuity test
• Random dot stereogram
• No need for Polaroid
lenses
• Only for gross and low
grade stereopsis
From Rosenbaum & Santiago, ClinicalStrabismus Management
#BasicMotilityExam (c) APSantiago 201912
13. 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
From Rosenbaum & Santiago, ClinicalStrabismus Management
#BasicMotilityExam (c) APSantiago 201913
14. Distance Stereotest
• Mentor BVAT
System
• Very good test
for assessing
control in X(T)
From Rosenbaum & Santiago, ClinicalStrabismus Management 1999
From Rosenbaum & Santiago,
Clinical Strabismus Management
#BasicMotilityExam (c) APSantiago 201914
15. Sensory Testing
• Worth 4 dot
• near: tests peripheral fusion
• distance: tests central fusion
• Retinal correspondence
• amblyoscope, Bagolini lenses
• 4 pd BO test: foveal suppression
• Normal response
• conjugate saccades OU,
• slow recovery in eye without the prism
#BasicMotilityExam (c) APSantiago 201915
16. 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
• Tests peripheral fusion
• At 6 m:
• 1.25 degrees
• Tests central fusion
#BasicMotilityExam (c) APSantiago 201916
17. Worth Dot Test Results
http://image.slidesharecdn.com
#BasicMotilityExam (c) APSantiago 201917
18. Amblyoscope or Haploscope
• Measures fusional vergence
amplitudes
• Angle of deviation
• Area of suppression
• Retinal correspondence
• Torsion
• Instrument convergence
#BasicMotilityExam (c) APSantiago 201918
From Rosenbaum & Santiago, ClinicalStrabismus Management 1999
19. Motor Testing
Ocular rotations
The Ideal Target
Anomalous head posture
Tests of Muscle Function
Light reflex tests
Cover Tests
Other Tests
#BasicMotilityExam (c) APSantiago 201919
20. Outcomes
• State laws of strabismus and
apply to clinical situations
• Evaluate ocular rotations
• Suggest clinical entities with
limited ocular rotations
• Perform correct technique of
measuring the deviation
• Enumerate characteristics of
ideal target when measuring
strabismus deviation
• Enumerate factors affecting
measurement
• Perform techniques that can
”find” hidden strabismus
• Perform tests of muscle
functions and know their
indications and interpretations
• Perform the different light reflex
tests, know their indications and
interpretations
• Perform the different cover tests
and know their indications
#BasicMotilityExam (c) APSantiago 201920
21. Ocular Rotations
• State laws of strabismus and apply to clinical situations
• Evaluate ocular rotations
• Suggest clinical entities with limited ocular rotations
#BasicMotilityExam (c) APSantiago 201921
22. Ocular Rotations
• Duction: monocular
• Version: binocular
• Alert to pattern deviations: e.g., A, V
• Grading scheme:
• e.g., inferior oblique & superior oblique
#BasicMotilityExam (c) APSantiago 201922
23. Agonist Muscle and its
Antagonist, Yoke, Synergist
• AGONIST: muscle that cause specific
eye movement
• MR: abduction
• LR: adduction
• SR: supraduction
• IR: infraduction
• SO: intorsion
• IO: excyclotorsion
• YOKE muscles: muscles that cause 2
eyes to move in same direction
#BasicMotilityExam (c) APSantiago 201923
• ANTAGONIST muscle:
creates movement opposite
that of the agonist.
• MR-LR
• SR-IR
• SO-IO
• SYNERGISTS: muscles moving
1 eye in the same direction
• Adduction: MR, IR, SR
• Abduction: LR, SO, IO
• Intorsion: SO, SR
• Extorsion: IO, IR
RMR
LLR
RSR
LIO
RLR
LMR
RIR
LSO
RIO
LSR
RSO
LIR
33. Measuring the Deviation &
The Ideal Target
• Perform correct technique of measuring the deviation
• Enumerate characteristics of ideal target when measuring
strabismus deviation
• Enumerate factors affecting measurement
• Perform techniques that can ”find” hidden strabismus
#BasicMotilityExam (c) APSantiago 201933
34. Motor Testing
• Primary gaze
• Right and left gaze
• Up and down gaze
• Right and left head tilt
• Oblique gazes, occasionally
• Near: primary and down gaze
#BasicMotilityExam (c) APSantiago 201934
35. Cover Tests
• Requirements:
• Appropriate correction
• Know if correction with or without prisms
• Accommodative target (above threshold)
• Distance:
• 6 m: 1/6 D of accommodation
• approximates infinity
• > 6 m: X(T)
#BasicMotilityExam (c) APSantiago 201935
36. The Ideal Target
• “Accommodative target” but Above threshold
• e.g. Snellen acuity 20/20
• present 20/50 to 20/70
#BasicMotilityExam (c) APSantiago 201936
37. The Ideal Target
• With sufficient detail and contour
• Should sustain interest
#BasicMotilityExam (c) APSantiago 201937
38. Toys as Targets
• One toy one look
• With detail
• May be coupled with a
light
• Sounds for tracking but
not vision testing
#BasicMotilityExam (c) APSantiago 201938
39. The Ideal Target
• Maximum plus, least minus correction
• Allows minimal accommodation at 6 m
• Accommodation exerted only 1/6 Diopter,
considered zero for strabismus measurement
purposes
#BasicMotilityExam (c) APSantiago 201939
46. Tests of Muscle Function
• Perform tests of muscle functions and know their indications
and interpretations
#BasicMotilityExam (c) APSantiago 201946
47. Tests of Muscle Function
• Forced duction test
• Force generation test
• Saccadic velocity analysis
• Electromyography
• Dynamic MRI
#BasicMotilityExam (c) APSantiago 201947
48. Indications
• Incomitant deviation
• Limited ocular rotation
• Distinguish between restriction and paresis/palsy
• Distinguish between paresis and palsy
#BasicMotilityExam (c) APSantiago 201948
49. 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
#BasicMotilityExam (c) APSantiago 201949
50. Advantages
• Help in deciding between treatment options
• Monitor improvement of paretic muscles
#BasicMotilityExam (c) APSantiago 201950
51. Tests of Muscle Function
• Paresis vs. restriction
• Forced duction test
• Force generation test
• Saccadic velocity analysis
• Differential intraocular pressure
#BasicMotilityExam (c) APSantiago 201951
52. EMG: Electromyography
• Limitations:
• may record activity even if muscle still paretic
• response suppressed by GA
• still used in some cases of Duane syndrome and
Botulinum injection
#BasicMotilityExam (c) APSantiago 201952
53. Passive Forced Duction
• Children > 7 yrs, adults
• Topical anesthetic
• Cover one eye: ensures
fixation
• Look as far as possible in
the direction of limited
ocular rotation
• Provide fixation target
• Watch out for “falling
off ” of eye
#BasicMotilityExam (c) APSantiago 201953
From Rosenbaum & Santiago, ClinicalStrabismus Management 1999
54. 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 conjunctiva fused in one layer
• limits stretching/tearing of conjunctiva
• provides firm grasp
#BasicMotilityExam (c) APSantiago 201954
60. Intraoperative Forced Duction Testing
• Perform routinely to feel “normal”
• Perform esp after resections
• may be ortho in primary
• overcorrection in certain gazes
• Perform after transpositions
• Intraoperative adjustable suture
• Perform after removing suspected restrictions
#BasicMotilityExam (c) APSantiago 201960
62. Pitfalls: Forced Duction
• Patient apprehension
• Errors in technique
• “Falling off”
• Failure to proptose for rectus or retropulse globe for obliques
• Succinylcholine (Anectine)
• Posterior restrictions
• Co-contractions
• Co-existing paresis and restriction
#BasicMotilityExam (c) APSantiago 201962
63. Active Force Generation
• Apply a counteracting force
• Using the same grasp on
limbus
• Counter-traction to feel
resistance
• WOF: corneal abrasion,
conjunctival hemorrhage
#BasicMotilityExam (c) APSantiago 201963
From Rosenbaum & Santiago, ClinicalStrabismus Management 1999
64. Active Force Generation
• Differential IOP
• Paresis vs. palsy
• Combined paresis and restriction
#BasicMotilityExam (c) APSantiago 201964
65. FDT, FGT, Diagnosis
Diagnosis Forced Duction Force
Generation
Mechanical
restriction
Restricted Normal
Muscle palsy Free Absent
Paresis &
restriction
Free Weak
#BasicMotilityExam (c) APSantiago 201965
Common pitfall: mild paresis
Correlate with saccadic velocity analysis
66. Saccadic Velocity Analysis
• Study eye movement velocity
• muscle activity
• return of muscle function
• EOG : problem when testing vertical saccades
• Infrared
• Scleral search coil
#BasicMotilityExam (c) APSantiago 201966
67. Office Saccadic Velocity
• Look at 2 separate targets
• At least 20 deg movement sufficient
• Compare
• briskness of agonist and antagonist
• with fellow eye
• Bring the eye where muscle has
• maximum function
• full unrestricted motion From Rosenbaum & Santiago, Clinical
Strabismus Management 1999
#BasicMotilityExam (c) APSantiago 201967
68. Pitfalls: Saccadic Velocity
• Errors in technique
• failure to bring eye
where muscle is still
functioning
• Pharmacologic
• Fatigue
• Time of day
From Rosenbaum & Santiago, ClinicalStrabismus Management 1999
#BasicMotilityExam (c) APSantiago 201968
69. Clinical Applications:
Saccadic Velocity Analysis
• Paralytic Strabismus
• Restrictive Strabismus
• Lost or slipped muscles
• Neurologic Disorders
• Myasthenia Gravis (MG)
• normal then weakens; use
with Tensilon
• Progressive External
Ophthalmoplegia (PEO)
• general slowing
• Inter-nuclear
ophthalmoplegia (INO)
• slowed adduction
• normal abduction
#BasicMotilityExam (c) APSantiago 201969
70. Slowed Saccadic Velocities
• LR palsy abduction
• SO palsy downgaze
• Moebius horizontal
• Myasthenia normal then slows
• Slipped/Lost reduced 20-50%
#BasicMotilityExam (c) APSantiago 201970
71. Light Reflex Tests
BrĂĽckner Test
Hirschberg’s corneal light reflex tests
Krimsky / Modified Krimsky
• Perform the different light reflex tests, know their indications and
interpretations
#BasicMotilityExam (c) APSantiago 201971
73. Hirschberg’s Corneal Light Reflex
• 3.5 mm pupil:
• 15 deg at pupil edge
• 30 deg between limbus
and edge of pupil
• 45 degrees at limbus
• Not a true linear relationship:
21 pd/mm decentration
From Rosenbaum & Santiago, ClinicalStrabismus Management 1999
#BasicMotilityExam (c) APSantiago 201973
74. Krimsky vs Modified Krimsky
• in front of deviating
eye (modified
Krimsky)
• underestimates true
angle
• better at near
From Rosenbaum & Santiago, ClinicalStrabismus Management 1999
#BasicMotilityExam (c) APSantiago 201974
75. LIGHT REFLEX, COVER TESTS
(Courtesy of R. Pena, MD)
MODIFIED KRIMSKY
#BasicMotilityExam (c) APSantiago 201975
76. Cover Tests
Cover Uncover Test
Alternate Prism Cover Test
Simultaneous Prism Cover Test
Prism Under Cover Test
• Perform the different cover tests and know their indications
#BasicMotilityExam (c) APSantiago 201976
77. Cover Uncover Test
• Must be performed
before alternate
cover test
• Cover test: tropia
• Uncover test: phoria
• also for fixation
preference
#BasicMotilityExam (c) APSantiago 201977
https://www.youtube.com/watch?v=f5HbIZi4u70
78. Alternate Prism Cover Test
• Prisms before deviated eye
• primary vs. secondary deviation
• Unless strabismic eye is preferred for fixation
• Evaluates total deviation: manifest (tropic) and
latent (phoric)
• End point: No movement of eyes
#BasicMotilityExam (c) APSantiago 201978
79. ALTERNATE PRISM & COVER TEST
Gold standard for
measuring deviation
LIGHT REFLEX, COVER TESTS
(Courtesy of R. Pena, MD)
#BasicMotilityExam (c) APSantiago 201979
80. Simultaneous Prism Cover Test
• Tropia under binocular conditions
• Monofixation syndrome
• Estimate angle of deviation
• Present prism and cover simultaneously
• Absence of movement in tropic eye means correcting
prisms are accurate
#BasicMotilityExam (c) APSantiago 201980
81. SIMULTANEOUS PRISM & COVER TEST
Used for monofixation
LIGHT REFLEX, COVER TESTS
(Courtesy of R. Pena, MD)
#BasicMotilityExam (c) APSantiago 201981
82. Prism Under Cover Test
• For Dissociated Vertical Deviation
• Evaluate one eye at a time
• Prism and cover presented to the same eye
• Separate true hypertropia by using BU prism
neutralization in other eye
#BasicMotilityExam (c) APSantiago 201982
83. PRISM UNDER COVER TEST
Used for DISSOCIATED
VERTICAL DEVIATION (DVD)
LIGHT REFLEX, COVER TESTS
(Courtesy of R. Pena, MD)
#BasicMotilityExam (c) APSantiago 201983
85. Cover Tests
Cover Test Indication
Cover Uncover Test Phoria
Alternate Prism Cover
Test
Total Deviation
Prism Under Cover Test Dissociated Vertical
Deviation
Simultaneous Prism
Cover Test
Monofixation Syndrome
#BasicMotilityExam (c) APSantiago 201985
86. Other Tests
Red Glass Test
Parks 3-step Test
Evaluation of Torsion
MRI for Imaging
#BasicMotilityExam (c) APSantiago 201786
87. Outcomes
• Know how to perform the red glass test and interpret
results
• Know the indication for the Parks 3-step test
• Perform the Parks 3-step test and interpret the results
• Enumerate the different tests for torsion and know
how to perform them
• Enumerate the indications for MRI for strabismus
#BasicMotilityExam (c) APSantiago 201987
89. Red Glass Test
#BasicMotilityExam (c) APSantiago 201989
https://entokey.com/diplopia-2/
RL
-drawn as patient sees it
-uncrossed diplopia: Esotropia
RL
90. Red Glass Test
#BasicMotilityExam (c) APSantiago 201990
https://entokey.com/diplopia-2/
-drawn as patient sees it
-crossed diplopia: Exotropia
L RLR
91. Red Glass Test
Right hypertropia
• red image below white image
• Drawn as patient sees it
#BasicMotilityExam (c) APSantiago 201991
https://entokey.com/diplopia-2/
92. Parks 3-step Test
• Isolated
cyclovertical
muscle palsy
#BasicMotilityExam (c) APSantiago 201992
93. Parks 3-step Test
Left Hypertropia
1. Of 8 cyclovertical
muscles: 4
LSO, LIR, RSR, RIO
2. Of 4 cyclovertical
muscles: 2
increase on R gaze: LSO,
RSR
3. Of 2 cyclovertical
muscles: 1
increase of L tilt: LSO
#BasicMotilityExam (c) APSantiago 201993
94. (Masked) Bilateral
superior oblique palsy
• V pattern
• Reversal of hypertropia
• Frame 1 and 3
#BasicMotilityExam (c) APSantiago 201994