This document provides an overview of assessing strabismus in children. It discusses classifying strabismus based on age, taking a thorough patient history, performing a visual assessment including visual acuity and binocularity tests, and conducting a sensory and motor assessment of eye alignment and eye movement. The motor assessment involves tests like cover testing, versions, ductions, and special tests like vestibular eye movements. Taking this comprehensive approach allows for correctly diagnosing the type and extent of strabismus and determining appropriate management options.

1. ASSESSMENT OF STRABISMUS IN
CHILDREN
AYESHA SARFRAZ
ORTHOPTIST
BSC(HONS.) ORTHOPTICS, FO (CANADA),
MPHIL SCHOLAR (KEMU)
COAVS,KEMU/MHL

2. STRABISMUS!
• Strabismus is a visual
problem in which the eyes
are not aligned properly
and point in different
directions. One eye may
look straight ahead, while
the other eye turns inward,
outward, upward, or
downward.

3. CLASSIFICATION
• Infants: Age <1 year
• Toddlers: 1 year- 4 years
• Children: 5years- 14 years
• Adolescence: 15 years- 17 years
• Adults: 18 years and above

4. APPROACH TOWARDS
STRABISMUS

5.  History
 Inspection/ Observations
 Vision assessment
 Refraction
 Sensory Assessment
 Motor Assessment
 Measurements
 Motility testing
 Ptosis/ Proptosis evaluatiion
 Pupil examination
 Special Tests/ Ancillary Testing
 Anterior & Posterior segment evaluation

6. HISTORY

7. Case History
There are three main reasons for taking a history before
beginning the examination:
• To acquired detailed information on the patient’s
symptoms, the probable time of onset and the possible
etiology and information concerning any treatment he
may already have had.
• To allow the examiner to establish a good relationship
between himself and the patient and thus gain the
patients confidence and ensure his cooperation.
• To enable the examiner to observe the patient under
normal conditions that may be helpful when making
the diagnosis and prognosis and deciding upon the
treatment.

8. HISTORY TAKING IN STRABISMUS
• Visual behaviour
– Clumsy? Visually Inattentive? Close viewing distance
• Past History
– History of patching
– History of spectacle wear & Type of strabismus
– History of trauma
– Previous surgery
– Strabismus surgery , Other ocular procedures &
Periocular Surgeries

9. • Birth History
– Age of gestation
– Birth weight
– Problems during pregnancy
– Type of delivery
– Late Cry Syndrome
• Developmental History
– Developmental Milestones
– Motor and speech development
– Delay of visual maturation

10. • Family history
– Presence of hereditary forms of strabismus
– Response to strabismus surgery of family
members
• Review of systems
– Neurologic symptoms
– Other systemic abnormalities

11. INSPECTION

12. • Epicanthi folds/ Nasal Bridge (Pseudo strabismus)
• Lid Fissure
– Ptosis
– Exophthalmos
• Abnormal Head Posture
• Facial Asymmetry
• Fixation Preference
• Nystagmus

13. VISION ASSESSMENT

14. OBSERVATION OF VISUAL RESPONSE
1. Ability to follow target
2. Visually directed reaching
3. Objection to Occlusion
4. Binocular fixation pattern/ Ten Prism Diopter test
5. CSM method.
• CSM – 6/9 – 6/6
• CSNM –6/36 – 6/60
• Unsteady central fixation < 6/60
6. Mirror test
7. Induce Tropia Test
8. Bruckner’s Test/ Red Reflex Test

15. INDUCED TROPIA TEST

16. Tests for Resolution Acuity
• Optokinetic nystagmus test(OKN)
• Preferential looking test(PLT) 3-12 months
– Lea Grating paddles
– Teller acuity Cards
• Visually evoked response(VER)
• Catford drum test.
• Cardiff acuity card test.
• Kay Pictures
• Lea Symbols
• ETDRS
• Snellen Chart

17. Objection to
Occlusion to
rule out
difference of
Vision between
two eyes
Bruckner’s for
Strabismus,
pupil symmetry,
cataract and
retinoblastoma

18. Estimation of Visual Acuity in Infants
VEP helpful in establishing
the presence of cortical
blindness & give an
estimation of visual acuity
OKN is helpful for sneak
peak into cortical activity
for vision assessment

19. Visual Acuity in Pre School Children
Lea symbolsKay picture test

20. Snellen chart for pre school
children

21. Visual acuity in School Children
Snellen charts for school
age children
ETDRS

22. Near Vision
1. Reduced Snellen test
2. Reduced Sheridan Gardiner
3. Reduced E test
4. Maclure book
5. Moorfields bar reading book
6. N series test
7. Lea symbols

23. IF NECESSARY, Go For…
• Visual Field Evaluation

24. • Contrast Sensitivity Asessment
Hiding Heidi Test Lea numbers

25. • Color Vision Assessment
Lea Color Vision Panel 16

26. Refraction

27. FUNDOSCOPY
CYCLOPLEGIC REFRACTION
PRESCRIBE THE APPROPRIATE
REFRACTIVE CORRECTION
VISION ASSESSMENT
ALSO RULE OUT THE DIFFERENCE OF
VISION BETWEEN TWO EYES FOR
AMBLYOPIA

28. SENSORY ASSESSMENT

29. • Fusion
– Sensory Fusion
– Motor Fusion
• Stereopsis

30. FUSION
Sensory Fusion
• Worth Four Dot Test
– At 6m
– At 1/3m
• Bagolini Glasses

31. Motor Fusion
Prism Reflex Test
In babies & young children by using 20
prism diopter Base out and look for the
movement of eye.
Prism Fusion range
By using horizontal and vertical prism bars
in cooperative children

32. Stereopsis
• Lang two pencil Test
• Lang I & II
• Titmus Fly Test
• Randot Stereo Test
• Frisby stereo Test
• TNO stereotest

33. Stereopsis

34. MOTOR ASSESSMENT

35. Assessment of Deviation
• Hirschberg test
• Cover test
• Alternate cover test
• Krimsky test
• Prism Reflection Test
• Alternate Prism cover test
• Prism Under Cover Test
• Synoptophore

36. Hirscberg Test
Krimsky Test

37. Cover test ,Uncover test , Alternate
Cover Test & Alternate Prism Cover Test

38. The cover test for tropias…
Observe the right eye as you cover the left eye…

39. What would you record this as?
Is it manifest or phoric?
Is there a fixing eye?

40. And this???

41. The Cover / Uncover Test…
This eye is exophoric.

42. Occluder is swiftly moved from one eye to the
other.
Allow the occluder to cover the eye long
enough for the patient to pick up fixation.
A prism could now be introduced.

43. Cover Test
Cover/ Uncover
APCT…

44. Information Gained from Cover
Testing
Manifest Deviation
• Type of deviation
• Size of deviation
• Speed to take up fixation
• Effect of accommodation on deviation
• Nystagmus
• Dissociated vertical deviation
• incomitance

45. Latent Deviation
• Type of Deviation
• Size of deviation
• Rate of recovery to achieve binocular single
vision
• Partial Recovery

46. Different types of targets and
noisy toys could be used for cover
testing in children at 1/3 m

47. Synoptophore
• Fusion slides are used
• Alternate cover uncover test is performed
• Patient’s angle of deviation is measured
objectively and subjectively

48. • To elicit the extent and quality of movement
of each eye
• to determine the presence of comitancy or
incomitancy
• to establish the integrity of the ocular
movement system and their neural pathways.
Ocular Motility Testing

49. • Use a spot light positioned at primary position
of gaze at 50 cm from the patient
• Always remove the patients glasses
• Give clear instructions to the patient
• An audible and colorful fixation target may
need to be used for young children

50. While check for the horizontal versions look for the
following:
• Up drift and down drift of the either eye
• Under action or over action of extraocular muscles
• Limitation (restriction of movement)
• Changes in the size of palpebral aperture
• Changes in the pupil size
• Changes in globe position

52. Ductions are tested monocularly and the
following noted:
 Excrusion
 Behavior of both eyes
 Whether the movement is smooth and jerky
 Nystagmus
 Change in the position of lids and globe
 Effect of fatigue
 Torsional movement
 Any discomfort on movement
 Abnormal head movements
Ductions

54. When testing vertical movements, look for
• Under action or over action
• Globe changes
• Sign of lid fatigue
• Down movement should be checked both with
and without holding the lid
• Check for A/V pattern in straight up and down
gaze

55. • Versions and ductions from the primary
position, into each of the diagnostic position
of gaze are assessed.
• Movements are graded on a 9 position scale
-4, -3, -2, -1, 0, +1, +2, +3, +4
• Zero represents a normal movement
Ocular Movements Grading

56.  One held in the primary position and the other:
to each side of the head for horizontal movement
above and below the head for vertical movements
 The movement, speed and accuracy of both eyes are
compared and any asymmetry between the eyes is noted
Saccadic Movement

57. Saccade testing in Infants/
Children

58. Testing of saccadic eye movement s is useful in:
 Comparing movement of the two eyes as this may
show slight limitations
 Suspected myasthenia gravis as fatigue may become
evident
 Suspected internuclear ophtthalmoplegia as
dysmetria may be evident

59. Note The Pursuit Followed By The
Saccadic Movement OU

60. • Also known as the Vestibulo Ocular Reflex,
Cephalic Reflex and Doll’s Head Maneuver
Vestibular Eye Movement

61. • Fast phase is a saccade, the slow phase is a
pursuit
• Move the drum or tape to the right you get
pursuit right for the slow phase followed by a
quick saccade left for the fast phase
Optokinetic Nystagmus

62. head is rotated briskly by the examiner,
first in the horizontal plane and then in the
vertical plane.
 VOR will result in eye movements equal and
opposite to head movements.
A normal response will indicate that the
muscle function is not impaired.
Doll's Head Test

63. Clinically, This test can also be very useful in
infants with childhood esotropia where there
is suspected lateral rectus weakness.

64. Swinging Baby Test
• based on the observation of a conjugate
deviation of the eyes in response to head
movement induced by rotation and is useful with
babies who will not respond to conventional
testing.
• The infant is held upright facing the examiner. The
examiner rotates him/herself and the infant
through 360◦ while observing the infant’s eyes.
• Post-rotational nystagmus in sighted babies will
only persist for a few seconds before being
suppressed.

66. • One ear is irrigated with cold water, nystagmus is
produced with the fast phase toward the opposite
ear
• When one ear is irrigated with warm water,
nystagmus is produced with the fast phase toward
the same ear
• COWS
• If you inject bilaterally: CUWDS
Induced Vestibular Nystagmus

67. HISTORY, INSPECTION, VISION ASSESSMENT (VF, CS, CV)
SENSORY ASSESSMENT
MOTOR ASSESSMENT
SENSORY FUSION
MOTOR FUSION
STEREOPSIS
QUANTIFICATION OF
STRABISMUS
MOTILITY TESTING
PTOSIS EVALUATION
SPECIAL TESTS/ ANCILLARY TESTING/ PUPILS
MANAGEMENT
OPTICAL
AMBLYOPIA THERAPY
ORTHOPTIC
SURGICAL

68. Let’s Start Testing!!!