Table Of Content6
Pediatric Ophthalmology
and Strabismus
Last major revision 2018–2019
2021–2022
BCSC
Basic and Clinical
Science Course™
Published after collaborative
review with the European Board
of Ophthalmology subcommittee
The American Academy of Ophthalmology is accredited by the Accreditation Council for Con-
tinuing Medical Education (ACCME) to provide continuing medical education for physicians.
The American Academy of Ophthalmology designates this enduring material for a maximum of
15 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with
the extent of their participation in the activity.
Originally released June 2018; reviewed for currency August 2020; CME expiration date: June 1, 2022.
™
AMA PRA Category 1 Credits may be claimed only once between June 1, 2018, and the expiration date.
BCSC® volumes are designed to increase the physician’s ophthalmic knowledge through study and
review. Users of this activity are encouraged to read the text and then answer the study questions
provided at the back of the book.
To claim AMA PRA Category 1 Credits™ upon completion of this activity, learners must demon-
strate appropriate knowledge and participation in the activity by taking the posttest for Section 6
and achieving a score of 80% or higher. For further details, please see the instructions for requesting
CME credit at the back of the book.
The Academy provides this material for educational purposes only. It is not intended to represent the
only or best method or procedure in every case, nor to replace a physician’s own judgment or give
specific advice for case management. Including all indications, contraindications, side effects, and
alternative agents for each drug or treatment is beyond the scope of this material. All information and
recommendations should be verified, prior to use, with current information included in the manufac-
turers’ package inserts or other independent sources, and considered in light of the patient’s condition
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THALMOLOGY WORLD NEWS; PREFERRED PRACTICE PATTERN; PROTECTING SIGHT.
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Cover image: From BCSC Section 8, External Disease and Cornea. Fluorescein brightly stains the
base of the herpes simplex virus epithelial dendritic lesions in a cornea after LASIK. (Courtesy of
Arie L. Marcovich, MD, PhD.)
Copyright © 2021 American Academy of Ophthalmology. All rights reserved. No part of
this publication may be reproduced without written permission.
Printed in China.
Basic and Clinical Science Course
Christopher J. Rapuano, MD, Philadelphia, Pennsylvania
Se nior Secretary for Clinical Education
J. Timothy Stout, MD, PhD, MBA, Houston, Texas
Secretary for Lifelong Learning and Assessment
Colin A. McCannel, MD, Los Angeles, California
BCSC Course Chair
Section 6
Faculty for the Major Revision
Robert W. Hered, MD
Katherine A. Lee, MD, PhD
Chair
Boise, Idaho
Maitland, Florida
Steven M. Archer, MD Gregg T. Lueder, MD
Ann Arbor, Michigan St Louis, Missouri
Rebecca Sands Braverman, MD Mary A. O’Hara, MD
Aurora, Colorado Sacramento, California
Arif O. Khan, MD Kristina Tarczy-Hornoch
Abu Dhabi, United Arab MD, DPhil
Emirates Seattle, Washington
The Academy acknowledges the American Association for Pediatric Ophthal mology and
Strabismus (AAPOS) and the American Academy of Pediatrics (AAP), Section on Ophthal-
mology, for recommending faculty members to the BCSC Section 6 committee.
The Academy also acknowledges the following committees for review of this edition:
Committee on Aging: Aaron M. Miller, MD, MBA, Shenandoah, Texas
Vision Rehabilitation Committee: Terry L. Schwartz, MD, Cincinnati, Ohio
Practicing Ophthalmologists Advisory Committee for Education: Alice Bashinsky, MD,
Primary Reviewer, Asheville, North Carolina; Edward K. Isbey III, MD, Chair, Asheville,
North Carolina; David J. Browning, MD, PhD, Charlotte, North Carolina; Bradley D.
Fouraker, MD, Tampa, Florida; Steven J. Grosser, MD, Golden Valley, Minnesota; Stephen R.
Klapper, MD, Carmel, Indiana; James A. Savage, MD, Memphis, Tennessee; Michelle S.
Ying, MD, Ladson, South Carolina
Eu ro pean Board of Ophthalmology: Wagih Aclimandos, MB BCh, DO, FEBO, EBO Chair,
London, United Kingdom; Peter J. Ringens, MD, PhD, EBO Liaison, Maastricht, Netherlands;
Georges Caputo, MD, Paris, France; Rosario Gómez de Liaño, MD, Madrid, Spain; Peng T.
Khaw, MD, PhD, London, United Kingdom; Birgit Lorenz, MD, PhD, Giessen, Germany;
Francis L. Munier, MD, Lausanne, Switzerland; Seyhan B. Özkan, MD, Aydin, Turkey;
Maria Papadopoulos, MBBS, London, United Kingdom; Nicoline E. Schalij-D elfos, MD,
PhD, Leiden, Netherlands
The Acad emy also wishes to acknowledge the following committee for assistance in
developing study questions and answers for this BCSC Section:
Self- Assessment Committee: Mitchell B. Strominger, MD, Chair, Boston, Mas sa chu setts;
Deborah M. Costakos, MD, Milwaukee, Wisconsin; Theodore Curtis, MD, Mount Kisco,
New York; Mark I. Salevitz, MD, Scottsdale, Arizona
Financial Disclosures
Academy staff members who contributed to the development of this product state that
within the 12 months prior to their contributions to this CME activity and for the dura-
tion of development, they have had no financial interest in or other relationship with any
entity discussed in this course that produces, markets, resells, or distributes ophthalmic
health care goods or services consumed by or used in patients, or with any competing
commercial product or service.
The authors and reviewers state that within the 12 months prior to their contributions
to this CME activity and for the duration of development, they have had the following
financial relationships:*
Dr Sands Braverman: Welch Allyn (C)
Dr Browning: Aerpio Therapeutics (S), Alcon Laboratories (S), Alimera Sciences (C),
Genentech (S), Novartis Pharm a ceu tic als (S), Ohr Pharm ac eut ic als (S), Pfizer (S), Regen-
eron Phar ma ceu ti cals (S), Zeiss (O)
Dr Fouraker: Addition Technology (C, L), Alcon Laboratories (C, L), KeraVision (C, L),
OASIS Medical (C, L)
Dr Gómez de Liaño: Alcon Laboratories (C)
Dr Grosser: InjectSense (O), Ivantis (O)
Dr Hered: Moria Surgical (P)
Dr Isbey: Alcon Laboratories (S), Allscripts (C), Bausch + Lomb (S), Medflow (C), Oculos
Clinical Research (S)
Dr Khaw: Isarna Therapeutics (C), Novartis (C), Santen (C)
Dr Lorenz: Bausch + Lomb (C), Bayer HealthCare Phar mac eu tic als (L), Clarity (L, S),
Novartis Phar ma ceu tic als (L, S), Spark Therapeutics (C)
Dr Miller: Alcon Laboratories (L), Credential Protection (O)
Dr Schalij- Delfos: Novartis (C)
Dr Tarczy-H ornoch: Amgen (O), Mylan (O)
The other authors and reviewers state that within the 12 months prior to their contribu-
tions to this CME activity and for the duration of development, they have had no financial
interest in or other relationship with any entity discussed in this course that produces,
markets, resells, or distributes ophthalmic health care goods or services consumed by or
used in patients, or with any competing commercial product or service.
* C = consultant fee, paid advisory boards, or fees for attending a meeting; E = employed
by or received a W2 from a commercial company; L = lecture fees or honoraria, travel fees
or reimbursements when speaking at the invitation of a commercial company; O = equity
ownership/stock options in publicly or privately traded firms, excluding mutual funds;
P = patents and/or royalties for intellectual property; S = grant support or other financial
support to the investigator from all sources, including research support from government
agencies, foundations, device manufacturers, and/or pharmaceutical companies
Recent Past Faculty
Daniel J. Karr, MD
Sylvia R. Kodsi, MD
Stephen P. Kraft, MD
Kanwal (Ken) Nischal, MD
Evelyn A. Paysse, MD
In addition, the Academy gratefully acknowledges the contributions of numerous past
faculty and advisory committee members who have played an important role in the devel-
opment of previous editions of the Basic and Clinical Science Course.
American Academy of Ophthalmology Staff
Dale E. Fajardo, EdD, MBA, Vice President, Education
Beth Wilson, Director, Continuing Professional Development
Denise Evenson, Director, Brand & Creative
Ann McGuire, Acquisitions and Development Manager
Stephanie Tanaka, Publications Manager
Susan Malloy, Acquisitions Editor and Program Manager
Jasmine Chen, Manager of E-Learning
Lana Ip, Senior Designer
Beth Collins, Medical Editor
Eric Gerdes, Interactive Designer
Lynda Hanwella, Publications Specialist
American Academy of Ophthalmology
655 Beach Street
Box 7424
San Francisco, CA 94120-7424
Contents
Introduction to the BCSC . . . . . . . . . . . . . . . . . . . . . . xix
Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1 The Pediatric Eye Examination . . . . . . . . . . . . . . . .3
Examination of Children in the Outpatient Setting . . . . . . . . . . . . 3
History and Examination: General Considerations and Strategies . . . . . . 3
Examination: Specific Ele ments. . . . . . . . . . . . . . . . . . . . . 5
Visual Acuity Assessment . . . . . . . . . . . . . . . . . . . . . 5
Red Reflex Examination and the Brückner Test . . . . . . . . . . . . 9
Dynamic Retinoscopy . . . . . . . . . . . . . . . . . . . . . . . 9
Visual Field Testing . . . . . . . . . . . . . . . . . . . . . . . 10
Pupil Testing . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Anterior Segment Examination . . . . . . . . . . . . . . . . . . 10
Intraocular Pressure Mea sure ment . . . . . . . . . . . . . . . . 10
Cycloplegic Refraction. . . . . . . . . . . . . . . . . . . . . . 10
Fundus Examination . . . . . . . . . . . . . . . . . . . . . . 12
PART I Strabismus 13
. . . . . . . . . . . . . . . . . . . . . . .
2 Strabismus Terminology . . . . . . . . . . . . . . . . . . . 15
Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Prefixes and Suffixes. . . . . . . . . . . . . . . . . . . . . . . 15
Strabismus Classification Terms. . . . . . . . . . . . . . . . . . 16
Abbreviations for Types of Strabismus . . . . . . . . . . . . . . . . . 17
3 Anatomy of the Extraocular Muscles . . . . . . . . . . . . 19
Origin, Course, Insertion, and Innervation of the Extraocular
Muscles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Horizontal Rectus Muscles . . . . . . . . . . . . . . . . . . . . 20
Vertical Rectus Muscles . . . . . . . . . . . . . . . . . . . . . 20
Oblique Muscles . . . . . . . . . . . . . . . . . . . . . . . . 20
Levator Palpebrae Superioris Muscle. . . . . . . . . . . . . . . . 22
Relationship of the Rectus Muscle Insertions . . . . . . . . . . . . 22
Blood Supply of the Extraocular Muscles. . . . . . . . . . . . . . . . 23
Arterial System . . . . . . . . . . . . . . . . . . . . . . . . . 23
Venous System . . . . . . . . . . . . . . . . . . . . . . . . . 23
Structure of the Extraocular Muscles . . . . . . . . . . . . . . . . . 24
Orbital and Fascial Relationships . . . . . . . . . . . . . . . . . . . 25
Adipose Tissue . . . . . . . . . . . . . . . . . . . . . . . . . 25
Muscle Cone . . . . . . . . . . . . . . . . . . . . . . . . . . 26
vii
viii Contents
Muscle Capsule . . . . . . . . . . . . . . . . . . . . . . . . . 26
The Tenon Capsule . . . . . . . . . . . . . . . . . . . . . . . 26
The Pulley System. . . . . . . . . . . . . . . . . . . . . . . . 28
Anatomical Considerations for Ophthalmic Procedures . . . . . . . . . 28
4 Motor Physiology . . . . . . . . . . . . . . . . . . . . . . . 31
Basic Princi ples and Terms. . . . . . . . . . . . . . . . . . . . . . 31
Ocular Rotations . . . . . . . . . . . . . . . . . . . . . . . . 31
Positions of Gaze . . . . . . . . . . . . . . . . . . . . . . . . 31
Extraocular Muscle Action . . . . . . . . . . . . . . . . . . . . 31
Eye Movements. . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Motor Units . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Monocular Eye Movements. . . . . . . . . . . . . . . . . . . . 33
Binocular Eye Movements . . . . . . . . . . . . . . . . . . . . 37
Supranuclear Control Systems for Eye Movement . . . . . . . . . . 40
5 Sensory Physiology and Pathology . . . . . . . . . . . . . 41
The Physiology of Normal Binocular Vision . . . . . . . . . . . . . . 41
Ret i nal Correspondence . . . . . . . . . . . . . . . . . . . . . 41
Fusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Selected Aspects of the Neurophysiology of Vision . . . . . . . . . . . 43
Visual Development . . . . . . . . . . . . . . . . . . . . . . . 44
Effects of Abnormal Visual Experience on the
Retinogeniculocortical Pathway . . . . . . . . . . . . . . . . 44
Abnormalities of Binocular Vision . . . . . . . . . . . . . . . . . . 47
Visual Confusion . . . . . . . . . . . . . . . . . . . . . . . . 47
Diplopia . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Sensory Adaptations in Strabismus . . . . . . . . . . . . . . . . . . 48
Suppression . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Anomalous Ret i nal Correspondence. . . . . . . . . . . . . . . . 50
Monofixation Syndrome . . . . . . . . . . . . . . . . . . . . . 51
6 Amblyopia . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Pathophysiology . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Classification. . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Strabismic Amblyopia . . . . . . . . . . . . . . . . . . . . . . 54
Refractive Amblyopia . . . . . . . . . . . . . . . . . . . . . . 54
Visual Deprivation Amblyopia . . . . . . . . . . . . . . . . . . 55
Detection and Screening. . . . . . . . . . . . . . . . . . . . . . . 56
Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Cataract Removal . . . . . . . . . . . . . . . . . . . . . . . . 57
Refractive Correction . . . . . . . . . . . . . . . . . . . . . . 57
Occlusion Therapy . . . . . . . . . . . . . . . . . . . . . . . 58
Pharmacologic or Optical Treatment. . . . . . . . . . . . . . . . 58
Binocular Treatment. . . . . . . . . . . . . . . . . . . . . . . 59
Complications and Challenges of Therapy . . . . . . . . . . . . . 59
Contents ix
7 Diagnostic Evaluation of Strabismus and Torticollis . . . 63
Obtaining a History in Cases of Strabismus or Torticollis. . . . . . . . . 63
Assessment of Ocular Alignment . . . . . . . . . . . . . . . . . . . 64
Diagnostic Positions of Gaze . . . . . . . . . . . . . . . . . . . 64
Cover Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Corneal Light Reflex and Red Reflex Tests . . . . . . . . . . . . . 67
Subjective Tests of Ocular Alignment . . . . . . . . . . . . . . . 68
Assessment of Eye Movements . . . . . . . . . . . . . . . . . . . . 71
Ocular Rotations . . . . . . . . . . . . . . . . . . . . . . . . 71
Convergence . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Fusional Vergence. . . . . . . . . . . . . . . . . . . . . . . . 72
Forced Duction, Active Force Generation, and Saccadic Velocity. . . . 73
The 3- Step Test. . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Tests of Sensory Adaptation and Binocular Function. . . . . . . . . . . 75
The Red- Glass (Diplopia) Test . . . . . . . . . . . . . . . . . . 75
Bagolini Lenses . . . . . . . . . . . . . . . . . . . . . . . . . 77
The 4Δ Base- Out Prism Test . . . . . . . . . . . . . . . . . . . 78
The Afterimage Test . . . . . . . . . . . . . . . . . . . . . . . 79
Amblyoscope Testing . . . . . . . . . . . . . . . . . . . . . . 79
The Worth 4- Dot Test . . . . . . . . . . . . . . . . . . . . . . 80
Stereoacuity Tests . . . . . . . . . . . . . . . . . . . . . . . . 81
Assessment of the Field of Single Binocular Vision. . . . . . . . . . 81
The Prism Adaptation Test . . . . . . . . . . . . . . . . . . . . 82
Torticollis: Differential Diagnosis and Evaluation . . . . . . . . . . . . 82
Ocular Torticollis . . . . . . . . . . . . . . . . . . . . . . . . 82
8 Esodeviations . . . . . . . . . . . . . . . . . . . . . . . . . 85
Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Pseudoesotropia . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Infantile (Congenital) Esotropia . . . . . . . . . . . . . . . . . . . 87
Pathogenesis . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Clinical Features and Evaluation . . . . . . . . . . . . . . . . . 87
Management . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Accommodative Esotropia . . . . . . . . . . . . . . . . . . . . . . 90
Pathogenesis and Types of Accommodative Esotropia . . . . . . . . 90
Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Management . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Acquired Nonaccommodative Esotropia . . . . . . . . . . . . . . . . 92
Basic Acquired Nonaccommodative Esotropia . . . . . . . . . . . 93
Cyclic Esotropia. . . . . . . . . . . . . . . . . . . . . . . . . 93
Sensory Esotropia. . . . . . . . . . . . . . . . . . . . . . . . 93
Divergence Insufficiency . . . . . . . . . . . . . . . . . . . . . 94
Spasm of the Near Reflex. . . . . . . . . . . . . . . . . . . . . 94
Consecutive Esotropia . . . . . . . . . . . . . . . . . . . . . . 95
Nystagmus and Esotropia . . . . . . . . . . . . . . . . . . . . . . 95
Incomitant Esotropia . . . . . . . . . . . . . . . . . . . . . . . . 95
Sixth Nerve Palsy . . . . . . . . . . . . . . . . . . . . . . . . 95
Other Forms of Incomitant Esotropia . . . . . . . . . . . . . . . 97
