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Book Review

Optical Coherence Tomography and OCT Angiography: Clinical Reference And Case Studies

Darrin A. Landry, CRA, OCT-C
Amir H. Kashani, MD, PhD

Bryson Taylor Publishing, 2016
ISBN–‐13:978–‐1523976867
ISBN–‐10:1523976861
www.BrysonTaylorPublishing.com

In the early days of retinal angiography, photographers often worked very closely with ophthalmologists, learning together as they explored the diagnostic uses of fluorescein angiography and unraveled the complexities of interpreting the fascinating images they were capturing. This spirit of scholarly collaboration between imager and physician continues today in a new book: Optical Coherence Tomography and OCT Angiography, Clinical Reference And Case Studies by Darrin Landry and Amir Kashani. These authors are both well respected in their respective fields as educators and authors. Together they have created a timely textbook that will appeal to members of both professions.

Before receiving an advance copy of this book for review, I anticipated that the content would focus almost exclusively on OCT angiography.  I was pleasantly surprised to find that although the book features OCT-A prominently, it is much more than a text on this new state-of-the-art technology. It appropriately places OCT-A in the context of multiple imaging modalities to assist in diagnosis of a variety of retinal conditions.

The authors have produced a book that is part tutorial, part clinical atlas, and a collection of over forty cases that “puts it all together” using multiple imaging modalities with clinical descriptions. The book is divided into three sections:

Section 1. OCT and OCT Angiography

The introductory section will be particularly useful to imagers as it includes a basic overview of OCT and OCT-A technology, followed by a discussion on pattern recognition, normal anatomy and layers of the retina, how to move the scan pattern, recognizing artifacts, EDI/FDI and a basic primer on OCT-A. The OCT-A primer explains how this technology scans through the z-axis and detects motion to identify the retinal vasculature including the deep retinal plexus.  It includes a discussion of artifacts specific to OCT-A . This section will be especially helpful to those new to OCT and OCT-A, and anyone preparing for certification as an OCT-C.

Section 2. Atlas of Images and Disease Pathology

This section is an atlas of retinal OCT findings organized in anatomical order from the vitreous to the choroid. For each condition, the text includes a brief discussion of the disease process, clinical findings, and appearance in multiple modalities. For each condition, there are multiple image examples providing a full spectrum of potential findings for that disease. For instance, there are over twenty different examples of epiretinal membrane. Novice imagers will find this variety especially helpful in learning to recognize different manifestations of a single condition. In addition to common retinal findings the book also includes good examples of less recognized conditions such as outer retinal tubulation (ORT) and reticular pseudodrusen. As expected, retinal vascular diseases include OCT-A examples along with SD-OCT and other imaging modalities including fluorescein and ICG angiography. Experienced imagers will recognize many of these conditions, but the addition of OCT-A will give them another viewpoint and expand their understanding of each disease.

Section 3. Case Studies

The final section of the book is a series of over forty cases where the authors combine a brief medical summary with appropriate imaging modalities for clinical correlation. This format fits well with the current trend of “case-based-learning” in medical education. In many of these cases, OCT-A dovetails nicely with other imaging modalities to increase our understanding of a disease process or help confirm a diagnosis. This quote from the book’s Preface describes the format well “These images are presented in the context of additional imaging modalities to aide the reader in making useful correlations.”

In conclusion, this timely book is well organized and thorough, without becoming unwieldy. It is easy to navigate between sections if you want a quick reference on OCT anatomy or to look for examples of specific retinal conditions and how they may appear on OCT, OCTA and other imaging modalities. With over a thousand images and forty cases, to say that this book is generously illustrated would be an understatement. It is an impressive collaboration between an ophthalmic imager and a retinal specialist that should appeal to a wide audience that would include ophthalmic imagers, retinal technicians, residents in training, and clinicians wanting a reference for clinical correlation between modalities.

From a personal standpoint, I think it’s great to have an ophthalmic imager making a significant contribution to the ophthalmic literature. Darrin’s collaboration with Dr Kashani serves as a model for what imagers can accomplish when we collaborate with physicians on a professional level.  The spirit of collaboration between professions is echoed several times in the book including this statement from the Introduction, “Constant and close communication between the physician and imager is very essential.”

Reviews like this often end with a cliché that suggests that everyone in the profession should “add this book to your collection” or “keep a copy on your bookshelf”. I’ve tried to avoid those clichés, but honestly, I am happy to have this book in my collection and plan to keep it handy in clinic for reference, especially as we integrate OCT-A into our own diagnostic armamentarium.

 

Ophthalmic Photography: Where Science Meets Art

Ophthalmic photography has long played an important role in the documentation and diagnosis of ocular diseases. Ocular photography is used to record medical conditions, track disease progression, and create illustrations for publication and education. The primary role of ophthalmic imaging however goes well beyond documentation in its ability to aid in diagnosis of a broad range of eye conditions. Treatment plans derived from the diagnostic information provided by ophthalmic images have benefited countless patients, as ophthalmologists use images for decision making purposes on a daily basis, and in some cases, rely on photographs as a “road map” to guide therapy.

The history of ocular photography dates back to the late 1800’s when Jackman and Webster described a technique for photographing the retina of a living human subject. The next fifty years witnessed a slow advancement in instrumentation and techniques. Photographic results were mostly inadequate due to slow film speeds, long exposures, and inconsistent light sources. In the 1950s electronic flash and 35mm cameras were adapted to ophthalmic instruments and modern ophthalmic photography was born.

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There is a compelling connection between this photographic discipline and our subject, the human eye; a connection that goes beyond the obvious parallels between eye and camera, cornea and lens, iris and aperture, retina and film. We use the visual art of photography to identify problems in another visual system – the eye itself. Optical instruments used to examine or photograph the eye often utilize the optics of the subject eye to help in visualizing the target pathology.

CarterR4

Ophthalmic photography can at times be simple or incredibly complex. Ocular tissues can be opaque, translucent, or transparent and may require different strategies to record these structures photographically. Enhancement of anatomic features is sometimes necessary, and can be achieved by using fluorescent dyes, monochromatic light, or specialized optical devices and techniques to adequately document subtle pathology that would otherwise not be visible.

Bennett Cataract

Creativity and aesthetics have their place in this field and many ophthalmic images transcend their scientific purpose and achieve artistic merit, but it can be heartbreaking when the most photogenic or aesthetically pleasing subjects present themselves because a patient’s vision is severely compromised. Enthusiasm for creative imaging can suffer in the context of tragic loss of vision. This is balanced however, against those times when an imager captures great images that help preserve a patient’s vision. Unfortunately not all images will be of sufficient quality to warrant public display or publication. The challenge for ophthalmic photographers is to provide consistent clinical images of adequate diagnostic quality, even under adverse conditions.

RD Barr

By providing support for education, research, and clinical eye care activities, ophthalmic photographers have been an integral part of the professional eye care community for decades. As new diagnostic imaging and treatment modalities are developed, the role of the ophthalmic imager will evolve and continue to play an important role in the preservation of sight.

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