Advancing the Detection and Management of Diabetic Retinopathy with Ultra-widefield Retinal Imaging

US Ophthalmic Review, 2017;10(1):23–6 DOI: https://doi.org/10.17925/USOR.2017.10.01.23

Abstract:

The incidence of diabetes in the US population has increased more than fourfold over the last several decades and a high proportion of these patients manifest diabetic eye disease, including diabetic retinopathy (DR) and diabetic macular edema (DME). Ultra-widefield (UWF) retinal imaging has emerged as a valuable tool in the evolving standard of care for DR, providing essential visualization of ischemia and related pathology across the retina, particularly in the periphery, where these signs may appear earliest but may not be detected by conventional fundus photography. Multimodal UWF imaging has helped correlate changes in the periphery with DR progression, providing important guidance for treatment planning and facilitating improved understanding of the underlying mechanisms of disease. Rapid capture, immediate retrieval and efficient sharing of UWF retinal images support a wide spectrum of care settings—including teleophthalmology programs—and facilitate patient education.
Keywords: Ultra-widefield retinal imaging, diabetic retinopathy, fluorescein angiography, retinal periphery, ischemia, pan-retinal photocoagulation, teleophthalmology
Disclosure: David M Brown is a consultant for Heidelberg, Optos, Optovue, and Zeiss.
Acknowledgments: Editorial assistance was provided by BioComm Network, Inc.

Compliance with Ethics: This study involves a review of the literature and did not involve any studies with human or animal subjects performed by any of the authors.

Authorship: The named author meets the International Committee of Medical Journal Editors (ICMJE) criteria for authorship of this manuscript, takes responsibility for the integrity of the work as a whole, and has given final approval to the version to be published.

Received: January 27, 2017 Accepted March 10, 2017
Correspondence: David M Brown, Retina Consultants of Houston, 6560 Fannin, Suite 750 Houston, TX 77030, US. E: dmbmd@houstonretina.com
Support: The publication of this article was supported by Optos. The views and opinions expressed are those of the author and do not necessarily reflect those of Optos.
Open Access: This article is published under the Creative Commons Attribution Noncommercial License, which permits any noncommercial use, distribution, adaptation, and reproduction provided the original author(s) and source are given appropriate credit.

Diabetic retinopathy (DR) is one of the leading causes of adult vision loss in the developed world.1,2 Epidemiological and demographic factors, including the rising rates of diabetes related to obesity and an aging population, are driving the incidence of diabetic eye disease inexorably higher. Over the past 35 years, the number of Americans diagnosed with diabetes increased fourfold, from 5.5 million in 1980 to 22.0 million in 2014.3 In 2014, approximately 8 million Americans with diabetes were undiagnosed, making the total incidence of the disease in the US more than 29 million, or 9.3% percent of the population.4 Analyses based on data collected a decade ago in the National Health and Nutrition Examination Survey (NHANES) suggest that nearly a third of all adults with diabetes in the US had signs of DR. This rate was even higher among specific populations of diabetic patients, with more than a third of Mexican Americans and nearly 40% of African Americans having diabetic eye disease. Patients in these groups were also more likely to present with severe disease and vision loss. Overall, an estimated 4.2 million adults had DR at that time and 655,000 had disease severe enough to be vision threatening.5 Given the data showing that the at-risk population has continued to grow at a similar rate, the clinical community must take aggressive action toward earlier identification and treatment of patients with DR. Meeting this challenge requires improved access to screening and referral as well as enhanced strategies for earlier detection, evaluation, treatment, and assessment of treatment success.

In this setting, digital, multi-modality ultra-widefield (UWFTM) retinal imaging (Optos, plc., Dunfermline, Scotland) provides a technological cornerstone for the evolving standard of care. With a single, non-contact capture, UWF retinal imaging allows high-resolution visualization of up to 82%, or 200 degrees, of the retina (producing the digital optomap®), displaying the most retinal surface area of any available imaging system.6 Optos systems incorporate a proprietary scanning laser ophthalmoscope (SLO) and ellipsoidal mirror, engineered specifically for UWF imaging. The SLO utilizes two low-power lasers that scan the retina simultaneously, with the green ‘red free’ wavelength (532 nm) permitting visualization of the sensory retina to the retinal pigment epithelium (RPE) and the red wavelength (635 nm) reaching deeper structures from the RPE to the choroid. The latest generation Optos UWF platform, California, utilizes enhanced optical hardware and software to improve resolution during scanning, producing clear, high-resolution images of virtually the entire retina. The automatic montage feature increases the field of view in many eyes to greater than 95%.7 California provides multi-modality imaging options including color, autofluorescence (AF), fluorescein angiography (FA), and indocyanine green angiography (ICG).

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Keywords: Ultra-widefield retinal imaging, diabetic retinopathy, fluorescein angiography, retinal periphery, ischemia, pan-retinal photocoagulation, teleophthalmology