New Study Confirms the Equivalence of optomap to ETDRS Gold Standard for Grading Diabetic Retinopathy

November is Diabetes Awareness Month.  In 2015, 30.3 million Americans, or 9.4% of the population, had diabetes and approximately 1.25 million American children and adults had type 1 diabetes. These numbers are on the rise and the disease manifests with deleterious and deadly impact throughout the body – including the eye. An understanding of the disease, early detection and treatment are more imperative than ever.

 

A recent study cooperatively funded by the National Eye Institute, the National Institute of Diabetes and Digestive and Kidney diseases and the US Department of Health and Human Services concluded  that optomap ultra-widefield (UWF™) retinal imaging is a useful diagnostic tool for detection and assessment of severity of diabetic retinopathy (DR). The study published recently in JAMA Ophthalmology demonstrates that optomap UWF imaging can be used reliably in place of Early Treatment Diabetic Retinopathy Study (ETDRS) 7-Field imaging in clinical use and future clinical trials.  The paper, which builds off recent single site studies that found moderate to perfect agreement between the modalities, supports these findings through data acquired over a two-year period from multiple sites.

The gold standard assessment of DR severity has been based on grading of lesions within the ETDRS 7 standard fields. These 7 fields are time consuming in their acquisition, require dilation and once compiled represent only 34% of the retinal surface.  Advances in retinal imaging technology now allow UWF imaging to capture 82% of the retina in a single image and in less than ½ second without the need for dilation. This collaborative study offers that given the technological advances now enabling UWF imaging, and the potential benefits of this approach, there may be substantial impetus for moving to UWF imaging if it is compatible in determining DR severity, and if pathology in the retinal periphery provides additional clinically useful information on prospective worsening of retinopathy.

In this current multi-site study, there were 737 gradable eyes on both ETDRS 7-field images and UWF images masked to contain the same 7 fields after adjudication; 59% had exact agreement, and 96% were within 1 step of agreement.  The conclusion of the study clearly supported moderate to perfect agreement between modalities within the limited masked scope of the current gold standard.  As seen was seen in previous studies, when the area outside of ETDRS was assessed predominantly peripheral DR lesions (PPL) were present in 41.0% of these eyes and suggested increased DR severity  by 2 or more steps in 11.0%.

Cursorily referenced in this preliminary paper was a consideration of efficiency between modalities.  This initial study release notes that the use of UWF imaging in clinical settings not only increases the frequency of DR identification nearly 2-fold but also reduces acquisition time by more than half, ungradable image rate by 71% and image evaluation by 28% compared with non-mydriatic fundus photography.

The study suggests the possibility of UWF imaging becoming a preferred method of assessment of DR severity, not only because of moderate to perfect agreement between modalities within the ETDRS scope, but also because of the information found in UWF outside the ETDRS mask. This raises the question regarding the potential for detecting DR change and severity earlier.  Data collected from a previous study, suggests that lesions observed outside of the area captured within ETDRS may identify a possible subset of patients with the disease that may be more aggressive.  These lesions were found to suggest a 4.7 times greater risk of worsening to treatable DR over a period of four years.  That study also concludes that the identification of a subset of patients at greatly increased risk of experiencing DR progression and onset of proliferative DR that cannot be assessed by ETDRS 7-field imaging, would have important implications for the evaluation and care of diabetic eye disease.

The significance of the additional peripheral information gleaned through UWF imaging in assessing the risk of future DR progression will develop with the data collected from this ongoing study.  The complete study and summary document, as well as our entire clinical library is available on our website. We encourage you to learn more about the clinical benefits of utilizing ultra-widefield optomap in your practice or clinic.

Sources:
Comparison of Early Treatment Diabetic Retinopathy Study Standard 7-Field Imaging with Ultra Widefield Imaging for Determining Severity of Diabetic Retinopathy. Journal of American Medicine, 2018
Peripheral Lesions Identified on Ultra Widefield Imaging Predict Increased Risk of Diabetic Retinopathy Progression Over Four Years. Ophthalmology 2015

The Retina – A Window to Alzheimer’s Disease

In a novel study from Queen’s University Belfast, researchers demonstrate that the eye could be a window to the brain. The results of the study, recently published in the Journal of Ophthalmic Research, show how degenerative brain diseases such as Alzheimer’s Disease (AD) can be monitored via ultra-widefield (UWF) retinal imaging.  The retina is a part of the central nervous system and shares structural and functional features with the brain. Altogether 59 AD patients and 48 controls were entered into the study.  They were imaged utilizing ultra-widefield imaging from Optos.  This advanced technology, using red and green lasers, captures a 200 degree, high-resolution digital image of the retina in less than ½  second, reaching regions of the retina that have been previously inaccessible with other methods of imaging.

Measuring biomarkers, such as drusen and vasculature width gradients in delineated quadrants of the retina, the researchers found that these changes, particularly in the peripheral retina, could be associated with degenerative brain conditions such as AD. Specifically, the markers that were chiefly considered were drusen and vasculature changes. Drusen are deposits of fats, minerals, and proteins and are normal symptoms of aging that appear as yellowish spots in the layer beneath the retina.  While they are harmless and typically begin to appear after the age of 40, an increased occurrence in number and size can contribute to the degeneration of the retina.  In the study, at baseline and follow up, the optomap images revealed that drusen accumulation, particularly in the superior nasal quadrant, were increased and significantly associated with positive AD status as compared to the number of drusen that would be normally expected in the control group. An additional novel element of the study was that by utilizing the UWF view of optomap, the width gradient of the vasculature could be observed in entirety from the macula to the far retinal periphery.  The study found that people with AD have blood vessels that are wider closer to the macula and thin as they progress further into the periphery.  This can impede the flow of blood and the essential delivery of nutrients and oxygen in the periphery, leading to further damage.

The team, led by Dr. Imre Lengyel of Queen’s University, hypothesized that changes in the peripheral retina could be important to explore the association between the eye and the brain. They concluded that their research supported their original hypothesis and that UWF retinal imaging has significant potential for monitoring AD and other degenerative brain diseases via the eye.  Utilizing optomap to evaluate progression of AD may bring important value to this effort because changes in the eye are easier to measure in relation to other methods necessary to evaluate the health of the brain.  Establishing an evidential correlation between the eye and the brain would suggest that utilizing UWF imaging could provide an easier, more expedient access to that information.  Furthermore, UWF imaging provides a much less expensive option to other methods of evaluation, such as brain scans. The researchers demonstrated that by utilizing optomap, they were able to identify early markers that could manifest many years before dementia develops as well as high risk groups who would benefit from preventative guidance. The study notes that to be a reasonable marker of early disease, pre-symptomatic, or early symptomatic patients would need to be followed up over several years to determine the predictive value of the peripheral findings.  Routine optomap exams could prove to be an earlier, easier and more cost-effective method for monitoring the progression of AD, and identifying individuals at high-risk of developing AD.

Grading of vascular parameters on UWF imaging.

Read the Full Article here….
Or visit our website to learn more about clinical studies utilizing optomap technology.