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New pathway to monitor diabetic eye disease cuts waiting times

A new pathway to monitor people with stable diabetic eye disease has been shown by NIHR researchers to be safe and cost-effective, giving ophthalmologists more time to assess and treat people requiring their urgent care.

Published: 24 February 2023

Rising numbers of people with diabetic eye disease

Diabetic retinopathy is a common complication of diabetes that can result in vision loss and blindness. The conditions that lead to diabetic retinopathy - diabetic macular oedema (DMO) and proliferative diabetic retinopathy (PDR) - can both be successfully treated in most patients. Treated patients then need regular follow-up as both conditions may return.  

Approximately one third of the five million people with diabetes in the UK are affected by diabetic retinopathy. As the number of patients with diabetes continues to rise, so too does the pressure on ophthalmologists to manage more patients with new and existing eye disease and its complications. 

Professor Noemi Lois, Clinical Professor of Ophthalmology at Queen’s University Belfast, said: “Until now, ophthalmologists have needed to evaluate all patients with diabetic macular oedema and proliferative diabetic retinopathy - even those that are stable after treatment and who are doing well”. Such high demand for their time can lead to delays in diagnosing and treating DMO and PDR and increases the risk of vision loss.

One approach to reduce such delays is to train supporting allied non-medical staff (ophthalmic graders) to monitor the eye health of patients with previously treated and stable DMO and PDR. With a £800,000 award from the NIHR Health Technology Assessment Programme, Professor Lois led a team of researchers, ophthalmologists and patient representatives in a study to investigate whether patients could be successfully monitored without seeing an ophthalmologist at every appointment. 

Reducing waiting times to save sight

With support from NIHR’s regional Clinical Research Networks, the EMERALD (the Effectiveness of Multimodal imaging for the Evaluation of Retinal oedema And new vesseLs in Diabetic retinopathy) study recruited nearly 400 patients from 13 NHS hospitals across England, Scotland and Northern Ireland. All patients had previously undergone treatment for diabetic retinopathy (DMO and/or PDR) and underwent photographs and a scan of the back of their eyes for the study. 

Ophthalmic graders were trained to assess these images and scans to see whether the disease remained stable or had returned. A comparison of their assessments with an ophthalmologist’s review of the images and scans confirmed that trained graders could read images of active or stable DMO and PDR almost as accurately as ophthalmologists. 

Graders were particularly accurate when assessing scans of high-risk diabetic retinopathy. The study’s results were  published in the journals Ophthalmology and Health Technology Assessment.  

The team’s cost analysis, published in the British Journal of Ophthalmology, showed that this approach could save up to £1390 per 100 patients, but the main benefit was the time saved for ophthalmologists. As Professor Lois explained: “Ophthalmologists could use this time instead to treat patients who have active disease, either diabetic macular oedema or proliferative diabetic retinopathy, or both, thereby reducing delays around initiating treatment and saving patients’ sight”.

Their evidence that graders can successfully monitor patients with stable diabetic retinopathy has had a positive impact on NHS services across the UK. To date, 10 of the 13 study sites have incorporated some or all of EMERALD’s practices in their local Trust’s policies and guidelines. The remaining three hospital sites reported that EMERALD’s findings supported their existing practices, while also reassuring their eye care teams that the screening method was safe and effective. 

Consultant ophthalmologists Dr Clare Bailey and Dr Caroline Styles were members of the EMERALD research team and oversaw the research at their institutions. 

“EMERALD really helped to show how appropriate this type of pathway can be for diabetic retinopathy. It will transform the way we run our clinics in our local service and help to deal with ongoing capacity requirements.”

Dr Clare Bailey, consultant ophthalmologist, Bristol Eye Hospital.

Discussions with patient focus groups across England, Northern Ireland and Scotland revealed that although patients preferred face-to-face examinations with an ophthalmologist, they would accept graders’ assessments if the results were shared promptly. Ideally this would be at the same appointment where images and scans were obtained or immediately afterwards. Patients also wanted the opportunity to see an ophthalmologist from time to time. 

Commenting on the important role of focus groups, Dr Styles said: “The involvement of people with diabetes in this study reassures our population that these are safe and appropriate changes, and not just based on cost”. Details collected through EMERALD’s focus groups were published in the journal Eye.

Informing NHS eye care services and practice

EMERALD’s results received positive feedback from national ophthalmology specialists and have subsequently informed the National Eye Care Recovery and Transformation Programme’s guidance. The guidance, shared with NHS professionals via NHS Futures Eye Care Hub, supports all those involved in eye care services to improve care pathways, reduce treatment delays and minimise avoidable sight loss.

In addition, Professor Lois is a board member for the development of new NICE guidance on the treatment of diabetic retinopathy, which EMERALD’s results are also expected to help inform. The new guidance will be published in 2024.

The positive outcomes from EMERALD helped to successfully secure EU Horizon 2020 funding for the RECOGNISED project. RECOGNISED brings together researchers in diabetes, ophthalmology and neurology from nine EU countries, with the aim of using eye images and scans to identify patients at risk of developing cognitive impairment and dementia. Through better understanding of these conditions, the project aims to develop new ways to treat them. 

Reflecting on the EMERALD study’s findings, Professor Lois said: “I hope clinicians, not only in the UK but also across the world, take on board what we learnt in EMERALD. Re-designing services to take these results into account, i.e. shifting this work from ophthalmologists to graders, will increase capacity in eye services, which is so much needed, and thus save sight.”

The study was funded by the NIHR Health Technology Assessment (HTA) Programme.

More information about the study is available on the NIHR’s Funding & Awards website.

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