Co-Investigators: Alan Cruess, Bernard Hurley, Chris Rudnisky, David Wong, Jason Noble, Mahyar Etminan, Marie Carole Boucher, Matthew Tennant, Melanie Campbell, Sherif El Defrawy, Stephen Kosar, Tom Sheidow, Valeria Rac, Varun Chaudhary
Project Manager: Olivera Sutakovic
Diabetes – Most Common Cause of Blindness in Working Age Canadians
Diabetes is considered a global epidemic, affecting 8.5% of the worldwide adult population. By 2025, over 12% of the Canadian population will be living with diabetes. Those living with the disease have an elevated risk of eyesight deterioration. Chronically high levels of blood sugar can damage the back of the eye (retina) causing swelling, bleeding and scarring which can lead to deterioration and loss of eye sight. Diabetic Retinopathy (DR) is a serious, sight-threatening complication of diabetes and is the leading cause of blindness in adults under 60 years of age (working age). It is asymptomatic in the early stage, but can quickly progress to more advanced stages, such as diabetic macular edema (DME) or proliferative diabetic retinopathy (PDR); if left untreated, it can lead to severe vision loss, and even blindness.
Almost all people with Type-1 diabetes and more than 60% of those with Type-2 develop some form of retinopathy in the first 2 decades after a diabetes diagnosis.
Early detection of DR, by 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.
Diabetic Retinopathy is treatable
Diabetes Canada recommends that all people living with diabetes receive comprehensive eye exam by an ophthalmologist or optometrist every 1-2 years. More frequent screening is recommended for high risk individuals. Despite this recommendation, only 60% of people living with diabetes attend a regular eye examination, resulting in thousands of Canadians suffering loss of sight – a most feared complication of diabetes. 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 facilitated by telemedicine – Tele Retina – using mobile imaging system. These retina images are uploaded and hosted on a server; retina specialists can access them remotely to grade the level of retinopathy and provide a report with management recommendations. Currently more than 500 DR Tele Retina screening programs, 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. Despite these efforts, programs across the Provinces are not created equally and accessibility to retinal screening continues to be an issue. Furthermore, as we scale up this program, significant barriers in the time dedicated by nurses, technicians and physicians will exist as the taking and reading of retinal scans is still a largely manual process. Although the hope is to screen all Canadians at risk of DR, adjustments in the current practise of reading scans will have to be modified to ensure timely turn-around of diagnostics and therapeutics.
ii 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.
[ii] 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.
What Diabetes Action Canada is Doing to fill the gaps
Vision loss is of great concern for our patient partners and as such, Diabetes Action Canada endeavours to develop a national DR assessment program to prevent diabetes-related blindness and to address the barriers to eye examinations 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, preventing blindness and visual disability in both Ontario and British Columbia.
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 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 providing 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 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 modeling 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 segmentation of patients into higher and lower risk for treatment and follow up by primary or specialist care team.
A pilot project data, collected in collaboration with South Riverdale CHC, was analyzed by THETA for the cost effectiveness. Findings from this study suggest that tele-ophthalmology, using portable retinal camera, might be more cost effective way of screening for diabetic retinopathy than a standard screening in Toronto (semi) urban communities in diabetic individuals at risk for developing DR and with limited access to eye care specialists.
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.
In our newest project, with the team of scientists from Women’s Collage Hospital, we are testing different strategies for scaling up the DR screening program through Family Health Teams.
Furthermore, Diabetes Action Canada and OTN are also exploring collaborations with the Canadian National Institute for the Blind (CNIB) Mobile Eye Care van. This van serves over 30 communities in Northern Ontario and provides diagnostic and intervention services in eye care, as well as education to local health professionals. By collaborating with CNIB, Diabetes Action Canada has an opportunity to advance Indigenous community-based diabetic eye services in remote and underrepresented areas. Videos on this important work can be found here featuring Diabetes Action Canada co-investigator Dr. Stephen Kosar
On the National level, Diabetes Action Canada is currently developing a Diabetes Repository using anonymized patient data collected initially from Ontario, Alberta and Quebec. This repository will allow for expanded dataset of consenting patients with diabetes in multiple provinces with the ultimate goal to engage these patients to participate in Clinical Trials and/or monitor interventions. Using this repository, our team will identify the ophthalmology imaging software interface requirements to create a backbone of retinopathy data within this database. Retinopathy data in the Diabetes Repository will be used to create a feedback loop of reports that inform and improve communication between the diabetic retinopathy screening program, patients and health care provider.
As an exciting new initiative, Diabetes Action Canada is currently exploring a collaboration investigating the role of artificial intelligence (AI) in retinal image analytics with the Montreal Institute for Learning Algorithms (MILA). Using advanced technology to reduce the burden of the human interventions needed to process retinal scan images, this AI initiative will advance the improvement of care and outcomes of those individuals living with diabetes.