Diabetic-Retinopathy-Screening

Leads: Michael Brent, David Maberley

Co-Investigators David Wong, Varun Chaudhary, Stephen Kosar, Marie Carole Boucher, Matthew Tennant, Chris Rudnisky, Valeria Rac, Sherif El Defrawy, Jason Noble, Melanie Campbell, Bernard Hurley, Tom Sheidow, Mahyar Etminan, Alan Cruess

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 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).

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 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 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 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 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.

 

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 undertakes development of a national DR screening program. The DR screening program removes barriers to eye examinations access, provides early diagnosis and management of DR, and prevents blindness and visual disability.

In Ontario, in partnership with the 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 chronic disease management programs through Community Health Centres (CHC), Family Health Teams (FHTs), 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 and diabetes education to each person screened. Retinal images are uploaded to a server and  an ophthalmologist – retina champion – evaluates them in a timely manner.  Referral is made immediately for individuals at risk or those who require treatment for sight threatening DR, and the retina champions in each LHIN provide eye care. The screening program can diagnose previously undetected sight-threatening disease and is an excellent example of increasing accessibility for equity of care. There is potential for this program to scale-up 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 triage of patients into higher and lower risk for treatment and follow up by primary or specialist care team.

In collaboration with Laval University and Ottawa Health Research Institute, a research project was developed and is 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. Patient partners, affiliated with Diabetes Action Canada, and a number of community organizations in Ottawa, Montreal, Quebec City and Toronto helped us to recruit study participants. Patient partners input has been valuable in interview guided development process and interviewer training.  Phase 2 of the project will involve mapping barriers/enablers to behaviour change strategies and further collaboration with our patient partners. These results will enable the design of fit-for-purpose interventions that will specifically address the barriers experienced by these ethnocultural minority groups.

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. The goal is to identify interventions that have the greatest potential to increase screening rates across Ontario.

A pilot project’s data, collected in collaboration with South Riverdale CHC, was analyzed by Toronto Health Economics and Technology Assessment (THETA) for the cost effectiveness. Findings from this study suggest that tele-retina, using 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.

It has been challenging to identify and engage individuals with diabetes systematically. Furthermore, while tele-retina program has been successful in reaching at-risk individuals, it is currently not operating at full capacity. A continual alert system for both the patient and primary care provider is needed to monitor and remind them about annual DR screening and intervention necessary to prevent vision loss. The project OPEN, a population health management approach, will support the delivery of new models of care, and increase awareness in the communities and the number of people living with diabetes screened for DR.

On the National level, Diabetes Action Canada is currently developing a Diabetes Repository using anonymized patient data collected initially from Ontario, Alberta, Manitoba and Quebec. This repository dataset from multiple provinces will allow patients with diabetes who consented, to engage and participate in Clinical Trials and/or monitor interventions.  Using this repository, our team will identify the ophthalmology imaging software interface requirements and create a backbone of retinopathy data.  Retinopathy data in the Diabetes Repository will improve communication between the DR screening program, patients and health care provider with reports in a feedback loop.

As an exciting new initiative, Diabetes Action Canada is investigating the role of artificial intelligence (AI) in retinal image analytics with the group of scientists at University of Montreal, Polytechnique Montréal, and Montreal Institute for Learning Algorithms (MILA).  New algorithms are in development to analyze and grade retinal fundus photo images for diagnosis of diabetic retinopathy and other eye disease. 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.

 

  1. Felfeli; R. Alon; R. Merritt; M.H. Brent. Toronto tele-retinal screening program for 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.