Strabismus & Amblyopia

Alvina Pauline D. Santiago, MDNovember 2, 2016ASMPH

© AP Santiago 2016

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

Strabismus: Definition

Any misalignment of the eyes

❖  Manifest vs latent:

-tropia vs –phoria

❖  Direction

❖  Eso-

❖  Exo-

❖  Hyper-

❖  Hypo-

© AP Santiago 2016 © AP Santiago 2016

Strabismus

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Extraocular Muscles 1.  Medial Rectus2.  Lateral Rectus3.  Superior Rectus4.  Inferior Rectus5.  Levator Palpebrae

Superioris6.  Muller’s Muscle

http://www.images.missionforvisionusa.org/anatomy/uploaded_images/eomMR-783818.jpg

© AP Santiago 2016

http://www.cambridgequestions.co.uk

Annulus of Zinn

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Spiral of Tillaux

www.cybersight.org

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Horizontal rectus muscles

Medial rectus Lateral rectus

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Vertical rectus muscles

Inferior rectus Superior rectus

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Oblique muscles

Superior obliqueInferior oblique

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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

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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

DepressionExtorts

Adducts

Superior Rectus

Annulus of Zinn

(superior tendon of

Lockwood)

7.7 from limbus

CN 3 superior

ElevatesIntorts

Adducts

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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

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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

EOM Muscle: Oblique IO & SO Muscle Origin Insertion Innervation ActionInferior Oblique

Shallow depression on orbital plate of maxilla

Infero-temporal

quadrant of sclera near the macula

CN 3 inferior

ExtortsElevatesAbducts

Superior Oblique

Lesser wing of

sphenoid but

Functional origin:

Trochlea

anterior: 12-14 mm

behind limbusposterior

17-19 mm behind limbus

CN 4 IntortsDepressesAbducts

© AP Santiago 2016

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

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

foldMuller’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

Orbital Apex

Anatomy and Function Correlation

http://lms.ecco-org.eu

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

© AP Santiago 2016

Ophthalmic nerve (V1) branches and distribution

http://emedicine.medscape.com/article/1873373-overview#a2 © AP Santiago 2016

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

© AP Santiago 2016

Maxillary Nerve Branches (V2)

http://emedicine.medscape.com/article/1873373-overview#a2 © AP Santiago 2016

Maxillary Nerve Branches (V2)

http://emedicine.medscape.com/article/1873373-overview#a2 © AP Santiago 2016

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

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

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

Ocular Motility: EOM Movement

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Laws of Ocular Motility: Hering’s Law

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Laws of Ocular Motility: Sherrington’s Law

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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

Strabismus Evaluation: Hirschberg’s Corneal Light Reflex

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Strabismus Evaluation: Bruckner Test

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Strabismus Evaluation

❖  Cover Uncover Test

https://www.youtube.com/watch?v=f5HbIZi4u70

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Strabismus Evaluation

❖  Alternate Cover Test

https://www.youtube.com/watch?v=U59OEkjoIGg © AP Santiago 2016

ALTERNATE PRISM COVER TEST

Gold standard for measuring deviation

Courtesy of R. Pena 2015

© AP Santiago 2016

Strabismus Evaluation

From Rosenbaum & Santiago, Clinical Strabismus Managemenment 1999

© AP Santiago 2016

© AP Santiago 2016

Strabismus Evaluation: Torsion

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

From Rosenbaum & Santiago, Clinical Strabismus Managemenment 1999

© AP Santiago 2016

Outline: Amblyopia

❖  Definition

❖  Diagnosis

❖  Treatment

❖  Lessons learned from PEDIG

❖  The Futurehttp://www.eyestudioinc.com/wp-content/uploads/2016/01/Amblyopia3.jpg

© AP Santiago 2016

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

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 Noordenhttp://www.ascrs.org/sites/default/files/styles/hall_of_fame/public/external-profile/

Von%20Noorden%20Formal%20Portrait%20001.jpg?itok=XvJmWnEs

© AP Santiago 2016

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

Amblyopia Diagnosis

❖  Fixation Preference

vonNoorden, Ocular Motility

© AP Santiago 2016

Fixation Preference

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Fixation Preference & Visual Acuity

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Vision Assessment

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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

Visual Acuity Testing

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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

http://pedig.jaeb.org/Studies.aspx

http://www.abcd-vision.org/amblyopia/ats-pedig.html

Amblyopia PEDIG Studies

https://www.slideshare.net/secret/gbB88iM5gZwHVh

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

Lessons learned from PEDIG 1.  Atropine = patching2.  10 = 15 3.  6 hours = full time

4.  2 = 65.  6 > 2

6.  Glasses alone works.7.  If not, then glasses+patching.

8.  Teenagers benefit from patching.

© AP Santiago 2016

❖  Amblyopia PEDIG Studies

© AP Santiago 2016

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

Amblyopia PEDIG Studies

=© AP Santiago 2016

Amblyopia PEDIG Studies (ATS 2)

For age 3-7 with severe amblyopia, 6 h = 10 h patching

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Amblyopia PEDIG Studies (ATS 2B)

For 3-7 y with moderate amblyopia, same results with 2 or 6h of patching© AP Santiago 2016

Amblyopia PEDIG Studies

© AP Santiago 2016

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

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

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Amblyopia PEDIG Studies

Daily = weekly atropine ❖  20/40 to 20/80 ❖  3-7 years

© AP Santiago 2016

❖  Amblyopia PEDIG Studies

© AP Santiago 2016

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

What more PEDIG?

http://www.imore.com

http://www.geek.com

http://www.cclonline.com/

http://icons.iconarchive.com © AP Santiago 2016

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

Amblyopia Treatment: The Future

❖  Advanced algorithms, electronics, materials

❖  Intermittent automatic electronic occlusion

http://www.treatlazyeye.in

VIDI Smart Glasses

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•  Dichoptic Treatment (Hess)•  Virtual Reality Games•  Repetitive Transcranial Magnetic

Stimulation (rTMS) [Thompson]

Amblyopia Treatment: The Future Treatment for amblyopic adults

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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

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Dichoptic Tetris

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Virtual Reality Games for Amblyopia

❖  0:33 The Oculus Rift

❖  0.38 – 1:29 How it Workshttps://www.youtube.com/watch?

v=KumScsJ0xNQ

© AP Santiago 2016

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