|
|
THIS ARTICLE IS BEST READ ON A PDF.
The sixth annual British Association of Retinal Screeners (BARS) conference was held recently in Blackpool. BARS is an organisation for anyone primarily involved in providing retinal screening services to people with diabetes, from technicians to optometrists, ophthalmologists to administrators.
The organisation aims to provide continuing educational, representational and support resource for those involved in screening, and one of the ways this is achieved is through the annual conference.
Progress report
Bridget Turner, head of healthcare and policy at Diabetes UK, provided an update on the progress made in establishing a national screening service for diabetes-related eye disease. Awareness of the disease was growing, she said.
At present, diabetes is the leading cause of blindness in people of working age in the UK and early treatment can prevent blindness in 90 per cent of cases. In recent times, there has been an increase in awareness among diabetics about the risk of blindness, from 50 per cent in 2000 to 63 per cent this year. Much has been achieved, Turner said, through the roll-out of the national screening service. In the last five years, 120 local programmes have been established in England and Scotland, along with a central programme in Wales and Northern Ireland. Around 76 per cent of these programmes are close to reaching milestone targets.
But although considerable progress has been made, Turner voiced concerns over the future of the national programme, particularly around ongoing funding. A lack of funds could adversely affect the continuity of care and provision of service to some of the more hard-to-reach and vulnerable groups, such as care home residents. She also raised concerns about the capacity of specialist eye clinics to deal with the increased referrals which would result from the expanded screening programmes.
Diabetes UK is currently reviewing all of the primary care trust screening programmes and plans to launch its Diabetes Information Bank early next year. The information bank will contain profiles of all PCT areas and their diabetes services, allowing them to be easily compared. Retinal screening would be a part of this, Turner said, and stressed that it needed to be maintained as an integral part of diabetes care, and not viewed in isolation.
Disease Update
Dr Richard Greenwood, chair of the National Screening Committee (NSC) project advisory group, gave a clinical overview of the disease today.
He discussed the incidence, pathogenesis and management of Type 1 and Type 2 diabetes, and highlighted the progression from normal glucose tolerance, through insulin deficiency/resistance and then impaired glucose tolerance to Type 2 diabetes – which he estimated affected between 2-5 per cent of the population. He noted diabetes was specifically associated with microvascular complications – which was why retinal screening was so important. He discussed the current treatments, such as various insulin regimens and lifestyle interventions, and pointed out promising new therapies such as the incretin mimetics, alpha-gamma PPAR agonists and CB1 receptor antagonists. In the end, he noted, good control of blood sugar, blood pressure and cholesterol/lipids could significantly reduce the risk of microvascular complications.
Dilogen de Alwis, consultant ophthalmologist and clinical lead for the eye screening service in Croydon, gave a talk entitled ‘A pragmatic approach to retinal screening’.
Given the context for a retinal screening programme making best use of limited funding and resources to find and treat those at risk of progressing to sight-threatening disease, de Alwis had some controversial points to make about the NSC grading protocols. Using examples of various conditions detected using digital retinal photography, he showed how important it was that screening was carefully linked into appropriate care pathways. It was easy to spend too much time on differentiating between ‘mild’ (R1) and ‘no’ (R0) retinopathy because they have the same management strategy – review in one year and education.
The main point of a screening programme should be to identify those with ‘moderate’ (R2) retinopathy who are at risk of progression to serious eye disease. These patients, he said, could be managed by education in good diabetic control under the care of the GP and/or specialist. He suggested these patients could be kept within the screening programme with early recall for photography at four- to six-month intervals. Severe (R3) retinopathy and diabetic maculopathy (M1) de Alwis said he would manage in a diabetic retinal clinic. He was very cautious about the use of laser in both of these cases, due to the tissue destruction involved. Good diabetic control in lower risk cases was always the preferred option, he said. However, in severe cases, where appropriate, patients could be fast-tracked to a laser clinic on the same day.
He concluded his presentation with a review of other conditions that can be detected and which practitioners have a legal duty of care to manage. He demonstrated how this can be managed effectively using suitable care pathways which may be simply sending the digital images to the ophthalmologist for review or using an optometrist-led glaucoma screening clinic for those patients with suspicious discs.
Modern approaches
Ian Pierce, consultant ophthalmologist specialising in medical retina and vitreo-retinal surgery at a tertiary centre in Liverpool, described the modern approach to management of severe diabetes-related eye disease.
In cases of proliferative retinopathy the key is early detection and with timely laser treatment, which results in a 50 per cent reduction in severe visual loss. However, for those who don’t respond to laser or who are detected too late, a vitrectomy is done to remove the scar tissue following proliferation to prevent retinal detachment. This gives a good result -6/12 or better – in 70 per cent of cases. New advances using laser knives to prevent traction during surgery, and the smaller entry wounds which are self-closing, are improving these figures.
In focal maculopathy, laser can reduce oedema and reduce visual loss in 50 per cent of cases. Diffuse maculopathy is harder to treat with a focal grid laser. Using an OCT scanner reveals the cystoid spaces caused by traction from the vitreous base pulling on the macula. This is now treated by peeling off the internal limiting membrane in the macular region which removes the traction and is successful in 30 per cent of cases.
There are some new experimental treatments using intravitreal injections of anti-VEGF drugs such as Macugen, Lucentis and Avastin (recently in the news for their use in treatment of AMD). This is at a very early stage of investigation and there are issues relating to the risks of repeated injections, how often they are required and the long-term effects on the optic nerve; however initial results seem promising. There is also work going into developing a pill to reduce the effects of protein kinase C PKC-ß which increases in hyperglycaemia, leading to the production of VEGF and consequent proliferation.
New Certificate
Deborah Broadbent, training and education lead for the National Screening Programme, spoke about the new National Certificate in Diabetic Retinopathy which became available on October 1.
She detailed the evolution of the certificate from the NSF for diabetes, the retinopathy screening competence framework developed through Skills for Health and the award of National Occupational Standard status. Accreditation is through a City & Guilds level three, which has been approved by the Qualifications and Curriculum Authority. There are nine learning units, three of which are compulsory. The minimum number of units required is six and these must reflect the tasks undertaken by the particular role. There are exemptions from certain units for certain professions, for example optometrists. There is a single awarding centre based at the Cheltenham and Gloucester hospital. Further information on the courses can be downloaded at www.drscertificate.org. The associated assignments include short tests, case studies and grading exercises. One of the difficulties is finding assessors for the certificate, given this is a new qualification.
It should be noted that anyone becoming an assessor before taking the certificate will not then be able to sit for this at a later date. The certificate will become mandatory for everyone involved in diabetic retinal screening by 2008 as it is a quality assurance standard to have accreditation to be part of a screening programme.
Sarah Roberts, a diabetes specialist registrar at Chelsea and Westminster hospital, presented the results of a study on the questions patients ask at a retinal screening. The observational study showed 96 per cent of patients asked for an interpretation of the retinal images at the end of the photographic session. Nine per cent of patients with no retinopathy voiced concerns about future problems and how they could be prevented – this rose to 21 per cent of those who were found to have some degree of retinopathy. The conclusions drawn indicate that for service to be truly patient-centred, there is a need to grade the images at the time of service and provide a provisional assessment subject to future quality assurance. It was pointed out that this was an ideal opportunity for patients to be educated about diabetic control.
Grant Duncan, programme manager in London, discussed an audit into the non-diabetic lesions detected by a screening programme. In a 12-month retrospective study of 4,083 people attending at three locations, 23 per cent were found to have diabetic retinopathy. Of these, 11 per cent were referrable to ophthalmology. There were also 32 per cent with some form of non-diabetic lesion from drusen to melanoma, 10 per cent of which required referral to ophthalmology and 1.6 per cent which needed urgent referral.
The most frequent finding was cataract, followed by drusen, AMD, pigmented lesions, optic disc abnormalities, cellophane maculopathy, CRVO and CRAO, asteroid hyalosis, myelinated nerve fibres and A/V nipping.
The conference finished with the Lilly Lecture, which this year was given by Dr Richard Greenwood, retired diabetologist and chair of the NSC project advisory group. His talk was entitled ‘Screening for diabetic retinopathy: Are we on the crest of a wave or swimming against the tide?’.
Drawing on his experience in Norfolk, he described the ups and downs of starting a retinal screening programme. He said huge progress had been made, particularly with regard to developing a standardised approach, approved cameras and IT software, central funding for equipment, defined quality standards, accreditation, agreed performance targets and impressive progress made through the use of GP QOF reports.
However, he felt there were still unresolved issues related to programme size – 12,000 screenings per year and 500 cases per screener/grader raises issues for optometrists currently conducting screenings in practice. Funding for quality assurance, IT, the role of optometrists, increased workloads for ophthalmologists and the impact of screening programmes on integrated care also presented some concerns.
It was still difficult, Greenwood said, to get accurate data on the impact of diabetic retinal screening on blindness, but reports over the last 10 years show a drop in sight-threatening diabetic retinopathy, which he felt was an encouraging picture.
Acknowledgements
Figures 1, 2 and 3 are courtesy of Richard Haynes, Keeler/Optician competition entrant 2005, and show progressive changes in proliferative diabetic retinopathy.
Peter Mitchell is an optometrist in London and works in the retinal screening programme at the Homerton Hospital in Hackney