Gloucestershire Diabetic Eye Screening Service
01 August 2005
In 1995/6 Gloucestershire Primary Care Clinical Audit Group co-ordinated a countywide audit, which identified 9556 people with diabetes over the age of 16 (2.1% of the county's population). Of these, 5663 (59%) were under the sole care of their General Practitioner. There was no record of an eye examination in the previous 15 months in 25% of these and a further 7% had no record of the results of eye examinations that had taken place. In those who had been examined, retinopathy was recorded in only 18%, which suggested under reporting. A telephone survey of Gloucestershire GPs at that time confirmed strong support for a digital photographic screening programme.
The screening service covers a countywide population of 18,100 people with diabetes (Type 1 and Type 2) over the age of 12. Gloucestershire has a largely rural community and access to transport is difficult for people in outlying areas; particularly for older people, those with disabilities and those without a car. Providing screening at a convenient location appeared to be reaching people of lower socioeconomic status and some regular non attenders at clinics. There is a relatively low ethnic minority population in the county but there are a small number whose first language is Gujarati, Bengali or Hindi.
Why this service is a good example of shared practice
National Quality Assurance standards:
We believe that the service fulfils the following National Quality Assurance(QA) standards:
1. To reduce new blindness due to diabetic retinopathy - we are monitoring blind registration data to see if this is being achieved.
2. To identify and invite all eligible persons with known diabetes to attend for the DR screening test - all GP practices in Gloucestershire participate and we have > 98% of known people with diabetes on the register.
3. To ensure database is accurate - post office returns < 2%
4. To maximise the number of invited persons accepting the test - > 80% of people not already under the hospital eye service accept the test.
5. To ensure photographs are of adequate quality - 3.5% ungradable
6. To ensure grading is accurate- intergrader agreement standards have been achieved and internal QA standards introduced.
7. To ensure optimum workload for graders, to maintain expertise and avoid errors due to tiredness - all graders grade > 100 imagesets per annum. No-one grades > 4000 patient imagesets.
8. To ensure timely referral of people with R3 (fast-track) screening results (e-mailed or faxed) - 98% referred within 1 calendar week is being achieved for fast track
9. To ensure GP and patient, and shared care physician if appropriate, are informed of all test results - minimum is not currently being achieved of 70% <3wks results for routine grading because of a backlog of grading. We are working towards achieving this standard within the next 2 months.
10. To ensure timely consultation for all screen-positive patients - the achievable standard is being reached.
11. To ensure timely treatment of those listed by ophthalmologist - the minimum standard is being achieved.
12. To minimise overall delay between screening event and first laser - the minimum standard is being achieved.
13. To follow up screen-positive patients (failsafe) - currently not measured but this data will be collected as new software has been procured for the Ophthalmology department.
14. To minimise the anxiety associated with screening due to inappropriate referral - the achievable standard is being achieved.
15. To ensure timely rescreening - currently not being achieved as we run a biannual service.
16. To ensure the public and health care professionals are informed at regular intervals - we are commencing producing an annual report in 2005
Over arching aim:
To detect sight-threatening retinopathy in order to reduce the number of people who may lose their sight and require the assistance of relatives, carers and social services to maintain a good quality of life.
To detect sight-threatening diabetic retinopathy by means of digital photography and direct ophthalmoscopy
To provide a service that is accessible to people in rural and inner city areas of Gloucestershire
To allow people the flexibility of making their own screening appointments to suit their needs
To provide screening appointments out of working hours to encourage attendance of the employed population
To provide people with verbal health information relevant to diabetes eye health and the importance of maintaining good blood glucose control to reduce the risk of developing diabetic retinopathy
To provide robust biannual photographic screening (with a view to increasing to annual), ensuring people are informed of the need for an interim eye examination by GP, Optometrist, Diabetologist or Ophthalmologist whilst the screening service remains biannual.
Over the next year we anticipate a gradual move towards annual Eye examinations.
To provide clinics at Cheltenham General Hospital or Gloucestershire Royal Hospital for people who miss or who are unable to attend appointments at their GP practice
To ensure referrals are made to an Ophthalmologist when indicated and within the correct timescale
The screening programme currently provides a biannual service, looking to screen annually within the next 12 months when additional funds are available. The average uptake of screening is 74% of the population on first invitation.
Eye screening clinics are booked with General Practice surgeries 4-6 months ahead. The screening time allocated at a surgery depends on the numbers of people with diabetes registered within a practice. Patients? are sent a letter of invitation and an information leaflet about 4 weeks prior to the screening clinics. People are asked to phone their GP surgery to make an appointment convenient to them. Appointments are available from 08.30 daily except one day a week when the clinic starts later and runs until 5 -7pm depending on surgery closing times.
The screening equipment is taken to the surgery in a Volkswagen Transporter van adapted with a hydraulic wheel chair lift. The retinal camera and visual acuity chart are transported on purpose built trolley systems, which ensure safe handling for staff. Screening in the surgery ensures that people using wheelchairs can access the service.
At the screening appointment, a diabetes and ophthalmologic history is gathered from the person, and from visual acuity using a Logmar chart, the results of which are then recorded. The pupils are dilated with Tropicamide 1% drops, and an eye examination by means of digital imaging photography and ophthalmoscopy is conducted. Routinely, two, 45 degree fields of the macula and nasal are taken, with extra fields e.g. anterior or peripheral as necessary. Presentation of verbal education relating to diabetes eye health and the importance of maintaining blood glucose control within the normal limits to reduce the risk of developing complications of diabetes is also an essential element of the service. This is supported by viewing the retinal images which encourages interest and self-empowerment to the individual.
At the end of each day the image data is backed up onto CD. The digital images on the laptop are taken to the hospital and downloaded onto the hospital server. From here the images can be graded by trained personnel within a 2-4 week time scale (aiming for 2 weeks).
National Quality Assurance recommendations have been introduced:
Stage 1: A grader accredited to do so carries out a full disease grade on all image sets. Urgent referrals (R3) are passed for immediate assessment by an ophthalmologist.
Stage 2: A different grader assesses a random 10% of the no disease image sets and carries out a second full grade on all the disease image sets from the stage 1 grade. That second grader does not see the result of the first grader prior to grading.
Arbitration: If there is a difference of opinion about referral between the two graders then those image sets are referred onwards for an arbitration grade by an experienced grader or an ophthalmologist who decides whether or not the patient should be referred to the ophthalmology service or back into the screening programme. All referable imagesets are checked by an ophthalmologist prior to referral of the person with diabetes.
The images are graded following a standardised protocol which ensures those with retinopathy are dealt with appropriately and referrals made within the correct timescale. Previous years images are available to detect any diabetic changes between each screening episode. Images with urgent sight-threatening retinopathy are selected by the screener on site and graded urgently by an Ophthalmologist within 1 week.
People are referred to the hospital nearest to where they live. Three hospitals within Gloucestershire currently receive referrals to see retinal specialists. People who miss the clinics held at their surgery due to a holiday or sickness can be seen at Mop Up clinics held at a site each side of the county. There are clinics available each month and Primary and Secondary care professionals can also refer newly diagnosed people with diabetes, or anyone who has missed their screening appointment for whatever reason.
The people with diabetes, GP, Diabetologist and Ophthalmologist- where appropriate, receive a grading report following the screening. People who require referral to an Ophthalmologist are referred directly by the screening service to ensure it is an efficient and stream lined process.
Once graded, all images are archived onto CD and a compressed image (JPEG) is retained on the server with the electronic grading report for viewing if a person who has been screened is seen in the Eye clinic.
Features of the service
The service provides eye screening in a person's own surgery, so is accessible to the majority of the target population in a largely rural county. The service is friendly and efficient and popular with people with diabetes and professionals in both Primary and Secondary Care.
The retinal images are shared with people as an education tool whilst delivering important information on the connection between managing diabetes and eye care. Providing education at the time of screening has the potential to reinforce the importance of good glycaemic control to reduce the risk of complications associated with diabetes.
The funding is from the three Gloucestershire Primary Care Trusts with the responsibility for providing the service lying with Gloucestershire Hospitals NHS Trust.
A study was conducted that was accepted for publication in Diabetic Medicine (Scanlon, P. H., Malhotra, R., Thomas, G., Foy, C., Kirkpatrick, J. N., Lewis-Barned, N., Harney, B. & Aldington, S. J. The effectiveness of screening for diabetic retinopathy by digital imaging photography and technician ophthalmoscopy. Diabetic Medicine. 2003; 20 (6), 467-474).
The aim was to evaluate the introduction of a community based mydriatic digital photographic screening programme by measuring the sensitivity and specificity compared to a reference standard and assessing the added value of technician direct ophthalmoscopy.
For mydriatic digital photography, the sensitivity was 87.8%, specificity was 86.1% and technical failure rate was 3.7%. Technician ophthalmoscopy did not alter these figures.
These results are of a high quality and lessons were learnt from this study that have helped us produce a service, which would produce better results than this. For example, a slight change in the grading form for maculopathy to the one that is now being recommended for the English Screening Programme reduces uncertainty in the grading and would have improved our specificity to > 92%.
2. A workload study was also conducted, which has been accepted for publication by the British Journal of Ophthalmology.
The aim of this study was to determine how the workload of an ophthalmology department has changed following the introduction of an organised retinal screening programme, with respect to; new diabetic referrals, with retinopathy, cataract, and in total, and what the resource consequences of this are.
Providing a high standard quality assured annual service that can show a steady reduction in incidence and prevalence of people with diabetes losing vision and being registered blind.
The original aims and objectives of the service have been achieved except meeting the required frequency of annual screening. With increased funding an annual service can be sustained to meet the requirements of the National Service Framework and National Screening Committee recommendations.
The service requires support from professionals within both Primary and Secondary care. The Gloucestershire example is led by Ophthalmologists and its development is overseen by a manager for Head and Neck Services. The day to day co-ordination and development of the service is provided by a Screening Programme Manager. Responsibilities include the management of staff and service workload, and retinal screening and grading.
Three multi-skilled staff who are Registered Nurses or trained Ophthalmic Photographers have responsibilities for screening and grading. All personnel have undergone a course at the Hammersmith Grading Centre to correctly identify degrees of diabetic retinopathy. They have all received training to ensure they are skilled at ophthalmic photography and have an understanding of diabetes. A Senior Administrator oversees the administration of the service including generating patient letters, audit, and the referrals database.
The IT department at the hospital provides expertise to maintain the servers and Intranet which is essential for image download and grading.
The patient Information Department at the hospital is essential for registering newly diagnosed people with a unique screening number.
The success of the service relies on continued support from IT professionals both responsible for the camera and image capture software and the hospital grading and administration software.
The original funding from Gloucestershire Health Authority was £120,000 recurring in 1998 for 9,600 patients for a biannual service. Appropriate increases have been made and applied for to provide an annual service for 18,100 patients.
With appropriate funds and staffing it would be possible to effectively manage and provide a similar service in other areas or settings.
Teamwork and enthusiasm are essential to the success of the service as well as the continued support of Professionals and support staff in Primary care. Continual assessment of the screening procedure, audit and training and the development of staff are essential for the programme to evolve and adapt to the needs of service provision. It is essential to plan for the increasing numbers of people being diagnosed with diabetes as this has an impact on the frequency of service delivery.
Dr Peter Scanlon Associate Specialist - Ophthalmology
Mark Histed, Acting Programme Manager
Gloucestershire Diabetic Eye Screening Service
Cheltenham General Hospital