#ASMPH lecture to Year Level 7, November 2, 2016 on #strabismus and #amblyopia, including #PEDIG studies

1. Strabismus &
Amblyopia
Alvina Pauline D. Santiago, MD
November 2, 2016
ASMPH
© AP Santiago 2016

2. Outline: Strabismus
❖ Definition
❖ Muscle Origin & Insertion, Function, Innervation
❖ EOM Concepts and Muscle Movements
❖ Laws of Ocular Motility
❖ Adjacent Anatomical Structures with Functional
Correlations
© AP Santiago 2016

3. Strabismus: Definition
Any misalignment of the eyes
❖ Manifest vs latent:
-tropia vs –phoria
❖ Direction
❖ Eso-
❖ Exo-
❖ Hyper-
❖ Hypo-
© AP Santiago 2016 © AP Santiago 2016

4. Strabismus
© AP Santiago 2016

5. Extraocular
Muscles
1. Medial Rectus
2. Lateral Rectus
3. Superior Rectus
4. Inferior Rectus
5. Levator Palpebrae
Superioris
6. Muller’s Muscle
http://www.images.missionforvisionusa.org/anatomy/
uploaded_images/eomMR-783818.jpg
© AP Santiago 2016

6. http://www.cambridgequestions.co.uk
Annulus of Zinn
© AP Santiago 2016

7. Spiral of Tillaux
www.cybersight.org
© AP Santiago 2016

8. Horizontal rectus muscles
Medial rectus Lateral rectus
© AP Santiago 2016

9. Vertical rectus muscles
Inferior rectus
Superior rectus
© AP Santiago 2016

10. Oblique muscles
Superior oblique
Inferior oblique
© AP Santiago 2016

11. EOM Muscle: MR & LR
Muscle Origin Insertion Innervation Action
Medial
Rectus
Annulus of
Zinn
5.5 mm
from limbus
CN 3,
inferior
Adduction
Lateral
Rectus
Annulus of
Zinn
6.9 mm
from limbus
CN 6 Abduction
© AP Santiago 2016

12. EOM Muscle: Vertical SR & IR
Muscle Origin Insertion Innervation Action
Inferior
Rectus
Annulus of
Zinn
(inferior
tendon of
Zinn)
6.5 mm
from limbus
CN 3
inferior
Depression
Extorts
Adducts
Superior
Rectus
Annulus of
Zinn
(superior
tendon of
Lockwood)
7.7 from
limbus
CN 3
superior
Elevates
Intorts
Adducts
© AP Santiago 2016

13. Inferior Oblique
❖ Origin: Shallow
depression on orbital
plate of maxilla
❖ Insertion:
inferotemporal
quadrant of sclera near
the macula Rangeen Shandran R.
http://www.slideshare.net/RangeenChandran
© AP Santiago 2016

14. Superior Oblique
❖ Origin: Lesser wing of
sphenoid
❖ Functional origin:
Trochlea
❖ Insertion: curved
❖ anterior: 12-14 mm
behind limbus
❖ posterior 17-19 mm
behind limbus OM Patel, http://www.slideshare.net/ompatel9889
© AP Santiago 2016

15. EOM Muscle: Oblique IO & SO
Muscle Origin Insertion Innervation Action
Inferior
Oblique
Shallow
depression
on orbital
plate of
maxilla
Infero-
temporal
quadrant of
sclera near
the macula
CN 3
inferior
Extorts
Elevates
Abducts
Superior
Oblique
Lesser
wing of
sphenoid
but
Functional
origin:
Trochlea
anterior:
12-14 mm
behind
limbus
posterior
17-19 mm
behind
limbus
CN 4 Intorts
Depresses
Abducts
© AP Santiago 2016

16. Blood Supply
❖ ciliary arteries also arise from
these muscular arteries
❖ 7 branches
❖ 2 per rectus muscle except LR
which receives only 1
OM Patel, http://www.slideshare.net/ompatel9889
© AP Santiago 2016

17. EOM Muscle: Levator & Muller
Muscle Origin Insertion Innervation Action
Levator
Palpebrae
Superioris
Under
surface of
Lesser wing
of Sphenoid
Levator
Apo-
neurosis
CN 3
Superior
Lid
elevation;
Deepens
palpebral
fold
Muller’s
Muscle
(superior
palpebral
muscle)
Inferior and
bulbar
aspect of
Levator
palpebrae
behind the
fornix
Upper edge
of tarsal
plate
Sympathe-
tic fibers
Elevates
Lids
http://www.images.missionforvisionusa.org/anatomy/2006/03/extraocular-muscles.html © AP Santiago 2016

18. Orbital
Apex
Anatomy and
Function Correlation
http://lms.ecco-org.eu
© AP Santiago 2016

19. http://image.slidesharecdn.com/theorbit-140707121113-phpapp02/95/the-imaging-of-the-orbit-13-638.jpg?cb=1404735201
© AP Santiago 2016

20. Ophthalmic nerve (V1)
branches and distribution
http://emedicine.medscape.com/article/1873373-overview#a2
© AP Santiago 2016

21. http://image.slidesharecdn.com/theorbit-140707121113-phpapp02/95/the-imaging-of-the-orbit-15-638.jpg?cb=1404735201
© AP Santiago 2016

22. Maxillary Nerve Branches (V2)
http://emedicine.medscape.com/article/1873373-overview#a2 © AP Santiago 2016

23. Maxillary Nerve Branches (V2)
http://emedicine.medscape.com/article/1873373-overview#a2 © AP Santiago 2016

24. Cavernous Sinus Syndrome
❖ CN 3, 4, 6 palsy
❖ Optic neuropathy
❖ Oculo-sympathetic
paresis
❖ Impairment of
ophthalmic and
maxillary branch
of CN5
http://skullanatomy.info/individ%20spaces/orbit/04_brain_pan.jpg
© AP Santiago 2016

25. Cavernous Sinus Syndrome
❖ CN 3, 4, 6 palsy =
ophtalmoplegia
❖ Optic neuropathy
❖ Oculo-sympathetic
paresis: Horner
Syndrome
❖ Impairment of
ophthalmic and
maxillary branch
of CN5: sensory
loss
❖ Proptosis
http://emedicine.medscape.com/article/1161710-overview
© AP Santiago 2016

26. EOM Concepts & Movements
❖ agonist muscles
❖ antagonist muscles
❖ yoke muscles
❖ synergistic muscles
❖ Ductions & Versions
❖ dextroversion
❖ levoversion
❖ dextroelevation
❖ levoelevation
❖ Dextrodepression
❖ Levodepression
❖ Vergence Eye Movements
❖ Convergence
❖ Divergence
© AP Santiago 2016

27. Ocular Motility: EOM Movement
© AP Santiago 2016

28. Laws of Ocular Motility: Hering’s Law
© AP Santiago 2016

29. Laws of Ocular Motility: Sherrington’s Law
© AP Santiago 2016

30. Strabismus Evaluation
❖ Complete 5 point examination
❖ Gross
❖ Pupils
❖ EOM
❖ Intraocular Pressure
❖ Fundus evaluation
❖ Perform refraction
❖ Stereoacuity testing
❖ Strabismus Evaluation:
❖ Gold Standard: Alternate Prism Cover Test
© AP Santiago 2016

31. Strabismus Evaluation:
Hirschberg’s Corneal Light Reflex
© AP Santiago 2016

32. Strabismus Evaluation:
Bruckner Test
© AP Santiago 2016

33. Strabismus Evaluation
❖ Cover
Uncover
Test
https://www.youtube.com/watch?v=f5HbIZi4u70
© AP Santiago 2016

34. Strabismus Evaluation
❖ Alternate Cover Test
https://www.youtube.com/watch?v=U59OEkjoIGg
© AP Santiago 2016

35. ALTERNATE PRISM COVER TEST
Gold standard for
measuring deviation
Courtesy of R. Pena 2015
© AP Santiago 2016

36. Strabismus Evaluation
From Rosenbaum & Santiago, Clinical
Strabismus Managemenment 1999
© AP Santiago 2016

37. © AP Santiago 2016

38. Strabismus Evaluation: Torsion
From Rosenbaum & Santiago, Clinical
Strabismus Managemenment 1999 © AP Santiago 2016

39. From Rosenbaum & Santiago, Clinical
Strabismus Managemenment 1999
© AP Santiago 2016

40. Outline: Amblyopia
❖ Definition
❖ Diagnosis
❖ Treatment
❖ Lessons learned
from PEDIG
❖ The Future
http://www.eyestudioinc.com/wp-content/uploads/2016/01/Amblyopia3.jpg
© AP Santiago 2016

41. Amblyopia: Definition
❖ Etymology: dullness of vision
❖ Greek:
❖ amblus = dull
❖ Stem: ops = eye or vision
❖ Observer (MD) sees nothing,
and the patient sees very little
❖ von Graefe
❖ lazy eye
© AP Santiago 2016

42. Amblyopia: Definition
❖ Unilateral or bilateral decrease
in vision caused by pattern
vision deprivation or
abnormal binocular
interaction for which no cause
can be detected by physical
examination, and which in
appropriate cases, reversible by
therapeutic measures
❖ von Noorden http://www.ascrs.org/sites/default/files/styles/hall_of_fame/public/external-profile/
Von%20Noorden%20Formal%20Portrait%20001.jpg?itok=XvJmWnEs
© AP Santiago 2016

43. Amblyopia
❖ One eye sees better than the
other
❖ Developing visual system /
brain will ignore (suppress)
one eye
https://www.aapos.org/terms/conditions/21
© AP Santiago 2016

44. Amblyopia Diagnosis
❖ Fixation
Preference
vonNoorden, Ocular Motility
© AP Santiago 2016

45. Fixation
Preference
© AP Santiago 2016

46. Fixation Preference
& Visual Acuity
© AP Santiago 2016

47. Vision Assessment
© AP Santiago 2016

48. Pre verbal Vision Test
❖ Allen cards
❖ Cultural bias
❖ “dated”
❖ Based on experience
❖ Lea symbols
❖ more universal
❖ Same in every culture
❖ Equal blurr
© AP Santiago 2016

49. Visual Acuity Testing
© AP Santiago 2016

50. Letter Charts
http://cdn.ilovetypography.com/img/2015/07/Frear_figure8.png
http://precision-vision.com/wp-content/uploads/
2015/05/3d3b7d5d68132cc424920deb43e754bb_XL.jpg
© AP Santiago 2016

51. http://pedig.jaeb.org/Studies.aspx
http://www.abcd-vision.org/amblyopia/ats-pedig.html
Amblyopia
PEDIG Studies
https://www.slideshare.net/
secret/gbB88iM5gZwHVh

52. Definitions: PEDIG
❖ Mild Amblyopia: less than 20/40
❖ Moderate Amblyopia:
❖ 20/40 to 20/100 (ATS1)
❖ 20/40 to 20/80 (ATS2)
❖ Severe Amblyopia: 20/100 to 20/400
© AP Santiago 2016

53. Lessons learned from PEDIG
1. Atropine = patching
2. 10 = 15
3. 6 hours = full time
4. 2 = 6
5. 6 > 2
6. Glasses alone works.
7. If not, then glasses+patching.
8. Teenagers benefit from patching.
© AP Santiago 2016

54. ❖ Amblyopia PEDIG Studies
© AP Santiago 2016

55. Lessons learned from PEDIG
1. Atropine = patching
❖ Moderate amblyopia
❖ 3-7 years; younger than 8
❖ Strabismic = anisometropic amblyopia
❖ Atropine better tolerated
❖ Same rate of deterioration or improvement
❖ Same rate of recurrence
© AP Santiago 2016

56. Amblyopia PEDIG Studies
=
© AP Santiago 2016

57. Amblyopia PEDIG Studies (ATS 2)
For age 3-7 with severe amblyopia, 6 h = 10 h patching
© AP Santiago 2016

58. Amblyopia PEDIG Studies (ATS 2B)
For 3-7 y with moderate amblyopia, same results with 2 or 6h of patching
© AP Santiago 2016

59. Amblyopia PEDIG Studies
© AP Santiago 2016

60. Amblyopia PEDIG Studies
❖ 7 to < 18 y
❖ 20/40 to 20/400
❖ 27% Improves with glasses
alone
❖ 7-12 improved even if treated
previously
❖ 13-17 improved if not treated
previously
❖ Will it stay?
© AP Santiago 2016

61. Amblyopia Treatment Study-5 (ATS-5)
spectacles alone, then patch 2 hrs vs spectacles
❖ Ophthalmology 2006: 113 (6)
904-912.
❖ 5 wks: 1.1 lines treated; 0.5
lines specs
❖ Any visit average: 2.2 lines
treated; 1.1 lines specs
❖ After glasses, 2 hrs
patching (with 1 hr near
activity) improves
moderate to severe
amblyopia
https://t2.ftcdn.net
✚http://cdn4.teen.com
© AP Santiago 2016

62. Amblyopia PEDIG Studies
Daily = weekly atropine
❖ 20/40 to 20/80
❖ 3-7 years
© AP Santiago 2016

63. ❖ Amblyopia PEDIG Studies
© AP Santiago 2016

64. Lessons learned from PEDIG
❖ 2 hours works even for severe amblyopia
❖ When 2 hrs doesn’t work, additional push to 6h
improves 3 to <8 years with VA 20/50 to 20/400
❖ Bangerter filter = patching
❖ Levodopa-carbidopa promising
© AP Santiago 2016

65. What more PEDIG?
http://www.imore.com
http://www.geek.com
http://www.cclonline.com/
http://icons.iconarchive.com © AP Santiago 2016

66. Amblyopia Treatment Study-18 (ATS-18)
Binocular Computer Activities for Treatment of Amblyopia
Ended May 2, 2016
❖ To compare the effectiveness of 1 hour/day of binocular
game play 7 days per week (minimum of 4 days per week)
with 2 hours/day of patching 7 days per week, in children
5 to <13 years of age (younger cohort), as a non-inferiority
study.
❖ To compare the effectiveness of 1 hour/day of binocular
game play 7 days per week (minimum of 4 days per week)
with 2 hours/day of patching 7 days per week, in children
13 to <17 years of age (older cohort), as a superiority study.
© AP Santiago 2016

67. Amblyopia Treatment: The Future
❖ Advanced algorithms,
electronics, materials
❖ Intermittent automatic
electronic occlusion
http://www.treatlazyeye.in
VIDI Smart Glasses
© AP Santiago 2016

68. • Dichoptic Treatment (Hess)
• Virtual Reality Games
• Repetitive Transcranial Magnetic
Stimulation (rTMS) [Thompson]
Amblyopia
Treatment:
The Future
Treatment for
amblyopic adults
© AP Santiago 2016

69. Amblyopia Treatment: The Future
❖ Suppression caused amblyopia
(reverse paradigm)
❖ Dr. Robert Hess
Mc Gill University, CA
❖ Dichoptic Treatment: Tetris
❖ Improvement in 3D vision
❖ 1 hr/day for 2 weeks
http://www.treatlazyeye.in
VIDI Smart Glasses
© AP Santiago 2016

70. ©APSantiago2016

71. Dichoptic Tetris
© AP Santiago 2016

72. Virtual Reality Games for Amblyopia
❖ 0:33 The Oculus Rift
❖ 0.38 – 1:29 How it Works
https://www.youtube.com/watch?
v=KumScsJ0xNQ
© AP Santiago 2016

73. Repetitive Transcranial Magnetic
Stimulation (rTMS)
❖ Rapidly changing magnetic
fields applied to head with a
hand-held coil
❖ Weak electric currents induced
in the brain which excite
neurons in target areas
❖ Tx for migraine, Parkinson,
stroke, depression
❖ Visual loss in amblyopia not
due to loss of brain cells but
ongoing suppression
http://www.drchugh.com/images/rtms.png