Diabetic Retinopathy Screening


Prevent blindness through a Tele-retinal screening program

Determine the cost-effectiveness of Tele-retina screening

Consult with people living with diabetes to learn the barriers and enablers to diabetic retinopathy screening from the perspective of vulnerable populations

Identify and engage individuals at risk of developing diabetic retinopathy to start preventative screening

Identify and engage individuals at risk of developing diabetic retinopathy to start preventative screening


Marie Carole Boucher, Melanie Campbell, Varun Chaudhary, Alan Cruess, Sherif El Defrawy, Mahyar Etminan, Bernard Hurley, Stephen Kosar, Jason Noble, Chris Rudnisky, Tom Sheidow,

People living with diabetes have an elevated risk of vision loss. Chronically high levels of blood sugar can damage the back of the eye (retina) causing swelling, bleeding and scarring which can lead to worsening and even loss of eyesight. Diabetic Retinopathy (DR) is a serious, sight-threatening complication of diabetes and is the leading cause of blindness in adults under 65 years of age (working age).  It is asymptomatic in the early stage, but can quickly progress to more advanced stages; if left untreated; it can lead to severe vision loss and even blindness.

Prevent blindness through a Tele-retina screening program

Diabetes Canada recommends that all people living with diabetes have a special eye exam by an ophthalmologist or optometrist every 1-2 years.  Despite this recommendation, only 60% of people living with diabetes have a regular eye examination, resulting in thousands of Canadians suffering the loss of sight – a most feared complication of diabetes.

Early detection of DR, by a regular screening of the retina, is an effective method of avoiding vision loss from diabetes. There are effective therapies that can prevent visual loss and slow the progression of the damage if detected early. Therefore, it is critical to screen all people living with diabetes for early or more advanced diabetic retinopathy.

Younger adults with type-1 diabetes, Indigenous peoples, recent immigrants and residents of inner cities and remote areas have lower screening rates.  Unfortunately, we know that many people living with diabetes do not have access to regular eye examinations.  For those individuals, an eye exam can be performed using a mobile imaging system – telemedicine – Tele Retina. The retina images are uploaded on a server; retina specialists can access them remotely to grade the level of retinopathy and provide a report back to primary care provider with management recommendations.  Currently, more than 500 DR Tele Retina screening sites, serving both inner cities and remote areas, are operating in Ontario, Quebec, British Columbia, Alberta and Manitoba, with the majority of sites in Western Canada.  However, programs across the Provinces are not created equally and accessibility to retinal screening continues to be an issue.

At Diabetes Action Canada, we endeavour to develop a national DR screening program to prevent diabetes-related visual disability, blindness and to address the barriers to the screening access to all Canadians with diabetes. Our group is implementing a best practices approach with high potential to scale-up to other regions, for the early diagnosis and management of DR.

In Ontario, in partnership with Ontario Telehealth Network (OTN), Diabetes Action Canada plans to work with each Local Health Integration Networks (LHINs) to develop a customized and sustainable program that can integrate into existing regional chronic disease management program through Community Health Centres (CHC), Family Health Teams, Diabetes Education Programs and other services.  Dr Michael Brent, a national lead for our Diabetic Retinopathy Screening Goal Group, has developed a screening program with expert technologists in the inner city and remote communities with high rates of diabetes. Using a portable retina imaging system, a technician travels between sites, provides the DR screening eye exam as well as diabetes education to each person screened. Retinal images are uploaded to a server and evaluated in a timely manner by an ophthalmologist – retina specialist.  For those individuals at risk or who require intervention for sight-threatening DR, referral is made immediately and timely care provided by the retina champions in each LHIN.

This group has demonstrated the feasibility and the efficacy of diagnosing previously undetected sight-threatening disease.  The program has been deemed a priority project across all Ontario LIHN’s and provides an excellent example of increasing accessibility for equity of care and scale-up potential for this program in other Provinces and Territories.  For example, the DR screening program, under the leadership of Dr Stephen Kosar in conjunction with the Manitoulin Central FHT and OTN, is currently examining the entire population of Indigenous Peoples living with diabetes on Manitoulin Island.

In British Columbia, our Retinopathy Screening Goal Group co-lead Dr David Maberley is establishing the pragmatic evaluation of two new screening sites, one in the remote Bella Bella Heiltsuk First Nation community and one in east side downtown Vancouver. These will be highly valuable sites for modelling effective community-based diabetic retinopathy screening. Using new software for retina image data capture and transfer technology, this group aims to automate image analysis to improve efficiency and triage of patients into higher and lower risk for treatment and follow up by primary or specialist care team.


Determine the cost-effectiveness of Tele-retina screening

Using pilot project data, collected in collaboration with South Riverdale CHC, Dr Valeria Rac at the Toronto Health Economics and Technology Assessment (THETA) evaluated the cost-effectiveness of the Tele-retina program.  Findings from this study suggest that Tele-retina, using a portable retinal camera, is a more cost-effective way of screening for diabetic retinopathy than a standard screening eye exam in Toronto (semi) urban communities in diabetic individuals at risk for developing DR and with limited access to eye care specialists.

Consult with people living with diabetes to learn the barriers and enablers to diabetic retinopathy screening from the perspective of vulnerable populations

In collaboration with Laval University and Ottawa Health Research Institute a new research project was developed and now actively enrolling participants. Using structural interviews, the aim is to identify and understand barriers and enablers, ethnocultural minorities with the higher risk of DR (i.e. immigrants from South Asia, China and Francophone immigrants of African descent), are facing to attend DR screening in Ontario and Quebec. These results will enable the design of fit-for-purpose interventions that will specifically address the barriers experienced by these groups.

Identify and engage individuals at risk of developing diabetic retinopathy to start preventative screening

Diabetes Canada recommends that all people living with diabetes receive a special eye exam by an ophthalmologist or optometrist every 1-2 years; more frequently for high-risk individuals. Recent data shows only 60% of people living with diabetes have an eye examination, resulting in thousands of Canadians suffering a loss of sight.  Using provincial administrative databases and the National Diabetes Repository, we plan to identify those living with diabetes who have not received an eye exam in over two years.  We then plan to engage these individuals through their community health centres or primary care practitioner and invite them to a Tele-retina screening site for diabetic retinopathy checkup.  By directly contacting these individuals we can improve patient awareness of diabetic retinopathy, increase screening rates and prevent vision loss.

Artificial intelligence and machine learning – automatic retinal images reading to detect diabetic retinopathy and other eye diseases

Reading of retinal images is time consuming and still a largely manual process. As we scale up the Tele-retina screening program, significant barriers in the time dedicated by technicians and physicians will exist.  Although the hope is to screen all Canadians at risk of DR, the reading of images will be a major constraint in the timely turn-around of diagnostics and therapeutics.  As an exciting new initiative, Diabetes Action Canada is currently collaborating with a group of investigators at the University of Montreal – Department of Ophthalmology, the Montreal Polytechnique, and Montreal Institute for Learning Algorithms (MILA) to investigate the role of artificial intelligence (AI) in retinal image analytics. This group of scientists are developing new algorithms using advanced technology to read retinal fundus photos and optical coherence tomography (OCT) images for diagnosis of diabetic retinopathy and other eye diseases.  The AI initiative will advance the improvement of care and outcomes of those individuals living with diabetes, improving access to eye care specialists and increasing clinician productivity.


Felfeli; R. Alon; R. Merritt; M.H. Brent. Toronto tele-retinal screening program for the detection of diabetic retinopathy and macular edema in urban and rural settings: a case series. Can J Ophthalmol. 2018 available on-line 23 Aug 2018 https://doi.org/10.1016/j.jcjo.2018.07.004

Boucher MC, Desroches G, Garcia-Salinas R, Kherani A, Maberley D, Olivier S, et al. Teleophthalmology screening for diabetic retinopathy through mobile imaging units within Canada. Can J Ophthalmol. 2008;43(6):658-68.

Hooper P, Boucher MC, Cruess A, Dawson KG, Delpero W, Greve M, et al. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of diabetic retinopathy. Can J Ophthalmol. 2012;47(2 Suppl):S1-30, S1-54.

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