Is Community Based Monitoring of Diabetic Maculopathy and Pre-proliferative Diabetic Retinopathy Safe?

1 Background Diabetes mellitus, as estimated by the International Diabetes Federation (IDF), affects 537 mil-lion people globally which is expected to increase to 783 million by 2045. DED is amongst the commonest and most feared complications of diabetes consisting of diabetic retinopathy and diabetic macular oedema. In 2020, world-wide, 103 million people were estimated to have DED, 15 million with vision threatening DED and 29 million having diabetic macular oedema, projected to reach 161 million, 45 million and 77 million respectively by 2045.

Until recently, DED has been the leading cause of blindness (Severe Sight Impairment, SSI) in the working age population in developed countries. However, since the introduction of screening for DED in the UK, along with improvements in diabetes and ophthalmological care, DED is no longer the leading cause of SSI in the UK. In Wales, new certifications for both sight impairment (SI) and SSI have fallen by 50% since screening commenced.

Screening for DED in Wales is performed by the DESW, utilising digital photography performed by trained photographers and the images are graded by trained readers, utilising standardised protocols and quality assurance. All cases of sight-threatening diabetic retinopathy (DR) i.e., severe pre-proliferative DR, proliferative DR and diabetic maculopathy require referral to ophthalmology for review and/or treatment. However, 2-dimensional (2-D) digital photography used by DESW, whilst adequate for assessing diabetic retinopathy lesions, cannot determine the presence of diabetic macular oedema (increased retinal thickness). Current screening uses surrogate markers for suspecting the presence of maculopathy such as exudates within 1 disc diameter of the fovea or microaneurysms and haemorrhages with an unexplained visual acuity of 6/12 or worse. Diagnosing diabetic maculopathy requires a 3-D camera using OCT technology to determine whether treatment or monitoring is required. On OCT imaging, a substantial number with suspected diabetic maculopathy do not have maculopathy and are either dis-charged back to DESW or remain under monitoring for years in HES without ever having treatment.

Many HES departments experience lack of specialists and available space to cope with the ever-increasing patient numbers, which has led to significant delays in treatment and in some cases irreversible SSI. Therefore, there is a need to consider new ways of conducting ophthalmology services and to allocate certain elements into the primary care sector. Examples already exist such as the national Eye Health Examinations Wales (EHEW) service, and the national low Vision Service Wales. Increasingly, Health Boards are developing locally enhanced primary eye care pathways in partnership with the HES, such as Ophthalmic Diagnostic and Treatment Centres for glaucoma and age-related macular degeneration. In some parts of England, OCT surveillance clinics have been incorporated into diabetic eye screening, requiring additional funding. Currently, due to the increasing workload and Covid-19 related disruption, DESW cannot take on this extra work.

The Covid-19 pandemic made pre-existing pressures on the HES more evident and whilst services are returning to normal, the backlog and pressure from the numbers of new patients make it extremely difficult for the already stretched HES and DESW to continue seeing patients and to catch up.

Pressures on the NHS will not diminish, even post pandemic. Irrespective of uncertainties relating to Covid-19, as well as the possibility of other pandemics in the future, investigating new ways of working are imperative to ensure irreversible sight impairment does not become an unintentional consequence of the intense pressure on the HES aside from the backlog from Covid-19. For efficient diabetic maculopathy management related clinical decisions, it is important to consider OCT central retinal thickness measurements and 3-D imaging of the macula as well as patient's visual acuity and comorbidities. The DESW pathway does not include this clinical information currently so patients with suspected diabetic maculopathy, based on surrogate markers (e.g., exudates near the fovea) must attend the HES to allow for further imaging and clinical examination to guide their management and treatment plan.

Thus, DESW referrals with suspect maculopathy are seen in the HES in either dedicated diabetes clinics or in general eye clinics. Hospital-based data collection of retinal images/OCT scans and subsequently virtual reviews have been implemented in the UK and around the world. During those hospital appointments, clinical examination, visual acuity measurement and OCT scans are undertaken with measurements of the central retinal thickness and based on clinical findings, only a small number of patients referred with suspect maculopathy require treatment at the time of referral. As a result, many patients are discharged to DESW or often monitored in the HES for many years without the clinical indication for any specific eye related treatment. This ongoing monitoring in secondary care increases further the number of necessary appointments for review whilst only a small number of patients are suitable for discharge, The study will investigate a proposed new care pathway, created in response to the Covid-19 pandemic and the consequent backlog of patients requiring referral to the HES for suspected diabetic maculopathy and pre-proliferative diabetic retinopathy which is potentially sight-threatening. Diagnosis of diabetic maculopathy requires examination by OCT to measure the thickness of the retina. Prior to Covid-19 referral to HES for OCT examination would take upwards of 6 weeks which is often an anxious time for people with diabetes. During Covid-19 screening was stopped and cases with suspected maculopathy were not reviewed at the HES. Therefore, a backlog has built up in ophthalmology and it is expected that there will be an increase in referrals from screening once the screening service (DESW) has returned to full capacity. Moreover, rules of social distancing to prevent Covid 19 transmission in secondary care outpatients' settings have further compromised the limited capacity of the screening service and HES.

The expected outcomes of the new pathway would be:

1. Improved patient experience related to more timely review and earlier treatment if required. 2. Reduced stress and anxiety related to referral to hospital-based ophthalmology. 3. Extra capacity, allowing those referred from DESW for diabetic maculopathy to be seen in the community with virtual review and subsequent management by the hospital eye service. 4. Creation of a closer working relationship between community-based optometrists and hospital-based ophthalmology 5. The ability for patients to be assessed quicker in a more convenient location which is closer to home 6. Positive impact on the carbon footprint.

1.1. Research Question Is the proposed primary care based optometric pathway, utilising tele-ophthalmology, for people suspected to have diabetic maculopathy, safe, feasible, acceptable, environmentally beneficial and economically viable in comparison with the current pathway where all persons with diabetes suspected of having maculopathy and pre-proliferative diabetic retinopathy are referred directly to the HES?

2\. Study Outline 2.1. Aims and Objectives Primary Aim: To pilot a primary care-based optometry pathway for the assessment of diabetic maculopathy and pre-proliferative diabetic retinopathy with virtual consultant ophthalmologist review in Hywel Dda University Health Board (HDdUHB).

Secondary Aims:

* To understand how the proposed alternative pathway would work in a real -world setting * To understand the feasibility and acceptability of such a pathway to people with diabetes * To estimate the resources required and related costs of the pathway compared to the current usual care process. * To estimate the change in carbon footprint that would result from changing location of care.

Objectives:

* To understand the patient experience of both pathways and their preferences for the future monitoring of their eye health. * To assess the time taken from referral by DESW to having OCT imaging and treatment, the percentage of people confirmed to have maculopathy and those requiring treatment and/or follow up of both pathways and the relevant healthcare resource use.

2.2. Method

2.2.1. Study Type This study is an unblinded randomised controlled trial to assess a new pathway for the management of diabetic maculopathy.

2.2.2. Study Overview

* Study design - randomised controlled trial * Participants - People with diabetes detected as having diabetic maculopathy or pre-proliferative diabetic retinopathy by the DESW and referred to hospital eye services in HDdUHB * Randomisation and blinding - Participants will be randomised but not blinded * Intervention type and number of visits - OCT imaging performed in either the community optometry practices or usual care in hospital eye services (OPD clinics). A single study visit for the imaging to be performed. * Method of data collection, tools, and measurement to be used - Data will be collected using Consultant Connect. The validated eye care PREMS will be used to understand patient experience of using each pathway. Semi-structured interviews with participants will be conducted and recorded, transcribed, and then analysed by themes.

2.2.3. Study Populations, Subject Selection, Recruitment and Study Schedule The study will recruit 150 people with diabetes referred to HDdUHB ophthalmology for diabetic maculopathy (M1) or pre-proliferative diabetic retinopathy (R2). This sample size is considered achievable based on the current waiting list size within HDdUHB for this population. HDdUHB R\&D delivery unit will consent participants into the study via telephone and will then randomise participants to either usual care or the community OCT pathway.

Figure 1 shows participant flow through the study.

Participants randomised to usual care will be booked an appointment by the pathway co-ordinator into the clinics currently run outpatient department (OPD) clinics. These patients will be reviewed through the standard processes for these clinics either face to face or virtually.

Participants randomised to the community optometry pathway will be booked an appointment with a participating optometry practice by the pathway co-ordinator. This will be the practice closest to home.

At the appointment an OCT image will be taken along with clinical examination and patient d-ta collected, as per case report form v5 18.11.2024. After the appointment all participants will be provided with a link to the questionnaire v7 04.10.2024 on JISC and asked to complete. Any person who indicates difficulty with completing online questionnaires will be contacted by the research nurse who will conduct the questionnaire by telephone.

OCT images, clinical examination, and patient data for participants in the usual care arm will be recorded on consultant connect and reviewed by the consultant ophthalmologist either in person or virtually according to current processes in OPD.

OCT images, clinical examination, and patient data for participants in the community OCT arm will be recorded on consultant connect and sent to the consultant ophthalmologist for review.

In both arms, the ophthalmologist will decide the ongoing management plan i.e. discharge, continued monitoring, treatment required. Results of the appointment and management plan will be provided to the patients via the post.

Failsafe will be built into both pathways with the pathway co-ordinator booking appointments and then confirming patients have attended those appointments. If the appointments are can-celled or patients are not able to attend the pathway co-ordinator will ensure appointments are rebooked at the earliest availability.

A stratified subset of partic

• Time from referral to being seen [Срок оценки: Time taken from enrollment ti first appointment within 3months]
• Prevalence [Срок оценки: At baseline]
• Hospital to Community PREM questionnaire [Срок оценки: Day 1]
• Total number of appointments in ophthalmology [Срок оценки: through study completion, an average of 1 year]
• Travel distance from home to appointment [Срок оценки: Through study completion, an average of 1 year]
• Costs associated with appointments [Срок оценки: Through study completion, an average of 1 year]