Table of Contents

SECTION I: PRINCIPLES

1. Refractive Status of the Eye

2. Incidence and Distribution of Refractive Anomalies

3. Development of the Ametropias

4. Accommodation, the Pupil, and Presbyopia

5. Fusion and Binocularity

SECTION II: ADJUNCT EXAMINATIONS

6. The Ophthalmic Case Historian

7. Visual Acuity

8. Contrast Sensitivity and Glare Testing

9. Color Vision

10. Ocular Motility

11. The Physical Examination

12. Pharmacology and Refraction

13. Anterior Segment Evaluation

14. Posterior Segment Evaluation

15. Visual Field Screening and Analysis

16. Clinical Electrophysiology

SECTION III: THE REFRACTION

17. Corneal Topography

18. Objective Refraction: Retinoscopy, Autorefraction and Photorefraction

19. Wavefront-Guided Refraction

20. Monocular and Binocular

21. Phorometry and Stereopsis

SECTION IV: ANALYSIS AND PRESCRIPTION OF OPTICAL CORRECTIONS

22. Analysis, Interpretation, and Prescription for the Ametropias and Heterophorias

23. Correction with Single Vision

24. Correction with Multifocal Spectacle Lenses

25. Prescription of Absorptive Lenses

26. Applied Optics of Contact Lens Correction

27. Clinical Optics of Contact Lens Prescription

28. Correction of Presbyopia with Contact Lenses

29. Optical Correction with Refractive Surgeries and Prosthetic Devices

SECTION V: SPECIAL CONDITIONS

30. Infants, Toddlers, and Children

31. Patients with Amblyopia and Strabismus

32. Patients with Anisometropia and Aniseikonia

33. Patients with High Refractive Error

34. Patients with Irregular Corneal Astigmatism

35. The Elderly

36. Patients with Low Vision

37. Patients with Ocular Pathology

Reviews

BOOK REVIEW
William J. Benjamin, Editor, Irvin M. Borish, Consultant;
Borish's Clinical Refraction, second edition
Butterworth-Heinemann -Elsevier, 2006; hardbound, 1694pp, US$195, ISBN-13:
978-0-7506-7524-6
Barry Masters
Received: 1 April 2008 / Accepted: 2 April 2008
# Springer-Verlag 2008
Visual acuity is taken for granted until it changes, and then
it adversely affects our ability to function. It is a supreme
tribute to the clinical skills and the plethora of optoelectronic
instruments that are available to optometrists and
ophthalmologists that they can determine the altered
refraction that is required to restore normal visual acuity.
Before the era of photorefractive surgery, before the era of
contact lenses, there were glasses (that is, two pieces of
glass that are polished in such a manner to achieve the
required alteration in the light paths by the process of
refraction), and they are mounted in a frame to be worn on
the bridge of the nose and the ears and thus remain
stationary with respect to the visual axes of the eyes. With
eyeglasses, as compared to hand-held single lens magnifiers
that were used for reading, the hands are free and the
glasses remain stationary with respect to movements of the
head and the body. In the history of inventions, eyeglasses
provide an example of a simple idea that when properly
implemented provides individuals with a great improvement
in their quality of life. What is the origin of high
quality spectacles?
In a thoroughly researched and beautifully illustrated
new book, Renaissance Vision from Spectacles to Telescopes
(Philadelphia, American Philosophical Society,
2007) Vincent Ilardi provides new evidence that 15th
century Florence was the center for the production of high
quality spectacles. While Venice during the same period
also produced eyeglasses, the emphasis was on items such
as mirrors, vessels and similar objects that resulted in
higher profits. The glass industry in Florence existed from
the early 13th century, and by the time of the middle of the
17th century it was producing high-quality glass that even
Venice could not surpass.
We now jump from 15th century Florence to the present
and introduce Borish's Clinical Refraction, Second Edition.
For this edition, William J. Benjamin served as the editor,
Irvin M. Borish served as consultant, and 58 clinicianscientists
contributed chapters. Both the editors and the
contributors deserve acclaim for their scholarly and clearly
written and superbly illustrated chapters that comprise this
one-volume tome on the principles and the clinical practice
of refraction and associated subjects such as color vision,
contrast sensitivity, ocular motility, and visual fields. The
extensive scope of this volume is indicated by additional
chapters on infants, toddlers, and children; patients with
amblyopia and strabismus; patients with anisometropia and
aniseikonia; patients with high refractive error; patients
with keratoconus and irregular astigmatism; the elderly;
patients with low vision; and a final chapter on the
refractive effects of ocular disease.
Borish's Clinical Refraction provides the reader with two
varieties of information.
First, the clear explanation of the science related to the
relevant topic; the anatomy, the physiology, the biochemistry,
the neural pathways, the pharmacology, the optics, the
materials and their optical and mechanical properties that
comprise the lenses of glasses and contact lenses. Second,
the art of the appropriate clinical practice that involves the
physical examination of the eyes, clinical measurement of
the optical properties of the visual system, measurements of
the shape of the cornea, the aberrations of the visual
system, and the logical approach to select and fit the
appropriate glasses or contact lenses, or the procedures of
various types of photorefractive surgery. The successful
clinician needs to know both the basic science as well as
the details of the procedures that are required for the
diagnosis and management of refractive eye conditions, and
the reference book provides the principles and the clinical
procedures for the diagnosis and the management of
refractive eye conditions. As expected, the bulk of the
volume is devoted to a detailed, critical and comprehensive
treatment of the following topics: the examination of the
visual system, the various techniques to measure refraction,
and the analysis and prescription of optical corrections.
The strengths of Borish's Clinical Refraction include the
following: (1) a single volume book that is up-to-date,
clearly written, well illustrated, and comprehensive, (2) the
high quality black and white illustrations and the color
illustrations and clinical photographs which provide graphical
understanding to the text, (3) the well-designed and
easily read and understandable tables which summarize,
compare and contrast various parameters and procedures,
(4) the full color clinical images which illustrate the
pathology, clinical techniques, diagnostic readouts, diagnostic
instruments, and the optical principles, (5) the
references which provide additional resources, and (6) a
detailed index..
I now point out the utility for clinical practice and the
detailed exposition of the basic principles that are found in
each chapter of Borish's Clinical Refraction. I will proceed
by pointing out the significant features of two chapters, in
order to illustrate the basis of my evaluation of this book.
Again, these examples serve as exemplars of the remaining
chapters in the book.
I begin with the chapter on corneal topography. The
shape of the anterior corneal surface is important for both
the diagnosis and the management of many ocular
conditions. Because about two-thirds of the refractive
power of the eye is located at the air/tear film interface
that is adjacent to the anterior surface of the cornea, it is
important to be able to determine the shape of the cornea. If
the cornea was a portion of a sphere, the task would be
simplified; of course, the human cornea is not spherical,
and that is only the beginning of the array of difficult
problems that must be solved to design and calibrate an
instrument that is capable of measuring the shape of the
cornea. It is of note that both Helmholtz and Gullstrand
independently worked on the problem of designing an
instrument to measure the shape of the cornea. In modern
times, the personal computer was used to calculate the
shape of the cornea from a target of concentric rings
(Placido disk); the results depend on the assumptions and
the limitations of the mathematical models and the details
of the calculation algorithm. The important points of this
chapter are the discussion of the accuracy and the
assumptions that are implicit in the calculation of corneal
shape. To emphasize these factors the authors have placed
them in a summary box: assumptions and limitations
inherent in standard keratometry. For example, in the
section on keratometer principles we learn that the
keratometer measures the radius of curvature of a small
region of the central cornea. The value of this chapter is a
critical discussion of the assumptions and the limitations for
each type of instrument that is used to measure corneal
shape. I stress this point, because so much of the
commercial marketing literature either ignores or provides
minimal discussion and evidence from peer-reviewed
publications that provide experimental data in support of
the accuracy and the precision of a particular instrument.
More modern instruments use proprietary reconstruction
algorithms to model the corneal surface. The Klein
algorithm is presented as one solution to the problems that
are inherent in the older two-dimensional algorithms that
were used in reconstruction of the corneal shape.
The highlights of the chapter on corneal topography
are the critical and detailed discussions of the comparison
of the various corneal-surface descriptors, the comparison
of the various videokeratoscopic instruments, the role of
alignment, focus and reference planes, the discussion of
color maps and their interpretation, as well as the critical
and important subject of the analysis of accuracy and
repeatability. Corneal topographical mapping is an important
measurement system, and the data is presented in
various color-coded forms: surface elevation maps,
dioptric corneal maps, axial curvature maps, instantaneous
curvature maps and ray-tracing refractive power
maps. The authors present a critical evaluation of the
various approaches for the display of topographical maps.
Wavefront refraction is the subject of another chapter
that illustrates the exemplary features of Borish's Clinical
Refraction. Today it is possible to measure optical aberrations
over the entire pupil that are smaller than the
wavelength of the incident light. The primary purpose of
wavefront aberrometers is to accurately measure the
aberrations of the eye. This is particularly important for
mitigating the unwanted effects of spherical aberrations and
coma that occur with refractive surgery. The goal of
developing wavefront refraction is to improve the precision
and the accuracy of both autorefractors and subjective
refraction for visible light. The wavefront distortion is
measured by the root-mean-squared wavefront error, and an
eye is considered to be emmetropic if the total distortion
over the pupil is minimal. The most common form of
wavefront sensor is the Shack-Hartmann wavefront sensor.
This wavefront sensor measures the slope or the spatial
derivative of the wavefront; the integration of the wavefront
slope yields the shape of the aberrated wavefront. The
authors provide excellent discussions of methods to
interpret the wavefront aberration function, how to classify
the aberrations in terms of Zernike polynomials, and a
comprehensive analysis of various metrics to access the
optical quality of the eye. Finally, they describe the
challenge of using wavefront measurement to prescribe
the most appropriate vision aids.
In summary, Borish's Clinical Refraction is a modern,
comprehensive, didactic approach to the principles and the
clinical practice of refraction. While the text emphasizes the
examination of the eye and the visual system, the methods
of refraction, and the prescription of various types of
spectacles and contact lens, there is also a detailed analysis
and discussion of the field of refractive surgery and
prosthetic devices. The book is a useful textbook on the
principles and the practice of refraction; the measurement
and analysis of refractive errors and the detailed steps to
treat, manage, and prescribe spectacles or contact lenses
that serve to ameliorate the refractive errors and thus
improve the quality of the patient's lives. The second edition
has many new features; for example, an expanded chapter
on patients with keratoconus and irregular astigmatism. An
important section is devoted to the special ocular conditions
that are of importance to the clinician. In conclusion, I
highly recommend this very practical book for its honest,
critical, comprehensive, and scholarly approach. BOOK REVIEW-2
Borish's Clinical
Refraction, 2nd Edition
William J Benjamin
St Louis: Butterworth Heinemann
Elsevier, 2006
1,694 pages, RPR $315.00
Reviewed by ALEXANDRA JAWORSKI,
Department of Optometry and Vision
Sciences, The University of Melbourne
E-mail: aaja@unimelb.edu.au
I am compelled to agree with the editor
that, like many books, this second edition
is better than the first. Beginning with the
basics, this book is smaller and has
coloured pictures. More seriously, the
extensive array of diagrams better illustrates
clinical procedures, underlying
principles and clinical findings and generally
makes the text more inviting. Despite
the reduced thickness, the new edition
covers previously addressed topics pertaining
to refractive error more comprehensively
and in light of recent advances in
research and clinical optometry.
You receive 'a set of steak knives' with
this edition. Despite the title, more than
refraction is addressed. The book is organised
into five sections: principles, adjunct
examinations, the refraction, analysis and
prescription of optical corrections, and
special conditions. Research and clinical
optometrists will recognise many of the 45
authors who provide the breadth of knowledge
across the 37 chapters.
Factors associated with refractive error,
relationships between ocular components,
refractive changes in children and adulthood,
progression of ametropias and control
strategies are well reviewed. These last
two discussions provide a sizeable source
of information to benefit patient management
and serve as a good foundation
for patient advice regarding progression
of ametropia. However, like most books,
recent research findings are occasionally
absent.
Methods of objective and subjective refraction
at distance and near, including
corneal topography, are particularly well
discussed. The inclusion of wavefront refraction
is in keeping with advances in
aberrometry that are aimed at improving
vision beyond the dioptre when correcting
ametropia and which perhaps will be
incorporated in more routine clinical examinations
in the not too distant future.
Various forms of refractive correction
are reviewed, including the optical and
clinical considerations of single vision
lenses, multifocal lenses, contact lenses
(including silicon hydrogels, options for
presbyopes and RGPs) and surgical strategies.
Although corrective techniques and
approaches are constantly changing, I
found the review of surgical procedures
informative. General procedures, side effects,
complications, contraindications and
clinical features of marginal and good candidates
are covered; topics that are important
when a patient presents with an
interest in refractive surgery or we think
we have identified a suitable candidate.
Chapters in the 'adjunction examinations'
section cover additional clinical
procedures to evaluate a patient's visual
function, including visual field assessment,
contrast sensitivity, colour vision
and electrophysiology, in light of recent
advances. Ocular examination techniques
of the anterior and posterior segments
are detailed and compare well with books
that focus solely on general optometric
procedures. These sections are particularly
useful for third year to final year optometry
students and clinical instructors.
Clear instructions on basic physical examination
techniques are provided to identify
systemic signs of conditions that have
ocular manifestations, and aid our diagnostic
power. Regardless of whether systemic
evaluation is actively performed,
the text and illustrations represent reminders
of physical signs we may notice
coincidently during the course of an
ocular examination.
The final section addressing special
conditions is a great concluding addition.
It reiterates and integrates important
issues and clinical techniques discussed in
previous chapters, which are appropriate
for examining particular patient populations,
such as the elderly, children and
patients with high refractive errors, low
vision and keratoconus. The final chapter
on the refractive effects of ocular disease
provides a nice summary, encompassing
both ocular and systemic conditions, to
aid diagnosis and management of your
patient, in light of their refractive error.
The editor advises that this book was
specifically written for the qualified eyecare
practitioner and advanced student.
This pitch is achieved and as no other
book covers the breadth and depth found
here, this edition qualifies as a valuable
reference in our bookshelves. Students
just commencing their optometric training
would find this book to be a worthwhile
investment and a valuable resource
for their subsequent student and working
years. The theoretical basis of many
clinical procedures is provided, in addition
to clear instructions on technique,
expected findings and factors that impact
on these tests. The theoretical basis serves
students and practitioners well, enabling
both to appreciate the rationale and application
of alternative clinical tests and
management.