Early Detection of Diabetic Retinopathy
Submitting Institution
University of AberdeenUnit of Assessment
Clinical MedicineSummary Impact Type
HealthResearch Subject Area(s)
Medical and Health Sciences: Ophthalmology and Optometry, Public Health and Health Services
Summary of the impact
Diabetic retinopathy is a leading cause of blindness in people of working
age. Screening
programmes for its early detection are therefore crucial. Following the
introduction of screening
programmes for diabetic eye disease, research carried out at the
University of Aberdeen enabled
the resulting images to be analysed by computer rather than manually, a
technique that has now
been adopted by Scotland's national screening programme. This has achieved
a significant
impact on patient health, as well as economic impacts for the taxpayer,
through cost savings, and
for the company that developed the screening software commercially.
Therefore this research has had impact in health and welfare by
influencing decisions and care
practices by a health service.
Underpinning research
Since 1996 the number of people with diabetes in the UK has increased
from 1.4 million to 2.9
million and, according to statistics produced by Diabetes UK, is predicted
to rise to 5 million by
2025. In the western world, diabetic retinopathy — a serious complication
of diabetes — is the
leading cause of loss of sight among individuals of working age and can
progress to an advanced
stage without any noticeable symptoms. Screening programmes are therefore
essential for the
early detection of the disease. Approximately 20% of people diagnosed with
type 2 diabetes have
early signs of retinopathy, but with early diagnosis and treatment,
blindness will be prevented in
90% of those cases.
Since 1993, the University of Aberdeen has conducted a research programme
comprising two
elements. In the first instance the team (Dr John Olson, NHS Consultant
Ophthalmic Physician;
Professor Peter Sharp, Head of the Department of Biomedical Physics and
Bioengineering
(became Emeritus in August 2012); and Professor John Forrester, Professor
of Ophthalmology
(became Emeritus in 2011) developed software to detect those features
common to the early
onset of diabetic retinopathy; microaneurysms, haemorrhages and exudates.
Secondly, they
evaluated the clinical benefit of the software and concluded there was a
strong case both for
commercialising the software itself and for introducing it into screening
programmes for diabetic
retinopathy.
The Aberdeen programme started at a time when retinal imaging technology
was analogue and
the early work on microaneurysm imaging involved the time-consuming and
invasive technique of
injecting dye prior to imaging (fluorescein angiography) — an approach
that was inappropriate for
routine clinical screening. In 1997, the team developed the first fully
automated programme for
detecting microaneurysms in fundus (retinal) camera images [1].
As digital fundus cameras came on the market, the Aberdeen team was
funded by the NHS
Health Technology Assessment (HTA) programme to look at the value of
digital imaging in
diabetic retinopathy. The findings of this project (2007) showed, for the
first time, that [2]:
- digital imaging was an effective method for detecting referable
(potentially sight-threatening)
retinopathy, with technical failure rates lower than those of
conventional
photography,
- dilation of the pupils was not normally required, thereby reducing
patient discomfort,
- a single image of each eye (rather than the usual two) was sufficient,
- automated grading could improve efficiency by correctly identifying
just under half the
population as having no retinopathy (though it was suggested that for
automated grading
to perform reliably, confirmation from a larger trial was needed),
- manual screening alone would be insufficient to deal with the
increasing prevalence of
diabetes,
- there was strong evidence that digital imaging was fit for
incorporation into the national
screening service.
In 2003, with funding from Scotland's Chief Scientist Office, a
multidisciplinary team in Aberdeen
evaluated the efficacy and cost-effectiveness of the automated grading
system using 14,406
images from 6,722 consecutive patients attending a regional diabetic
retinopathy screening
programme. The software performed disease/no disease decision-making based
on detection of
microaneurysms and dot haemorrhages, and furthermore was able to assess
image quality —
something that had not previously been considered. The automated system
was found to be as
effective as the manual grading system but more economical to operate. It
was estimated that, if
implemented within the national screening programme [3,4], it would save
the National Health
Service in Scotland approximately £200,000 per year.
In a further study begun in 2005, the team recruited over 25,000 patients
from three Scottish
screening centres with a view to monitoring the performance of a new
algorithm that incorporated
macular exudate and blot haemorrhage detection, both signs that may
require referral to an
ophthalmology clinic. This demonstrated conclusively that the detection of
observable/referable
retinopathy was improved [5].
References to the research
[1] Cree MJ, Olson JA, McHardy KC, Sharp PF, Forrester JV. (1997). A
fully automated
comparative microaneurysm digital detection system. Eye, 11:
622-628. This paper addressed,
for the first time, the difficult task of detecting microaneurysms in
fundus camera images in a fully
automated way (98 citations).
[2] Sharp PF. Olson JA, Strachan F et al. (2003). The value of digital
imaging in diabetic
retinopathy. Health Technology Assessment, 7:1-119. A health
technology study on the value of
digital fundus cameras which demonstrated that automated screening for
diabetic retinopathy was
feasible (33 citations).
[3] Philip S, Fleming AD, Goatman KE et al. (2007). The efficacy of
"disease/no disease" grading
in a systematic screening programme. Br J Ophthalmol, 91:
1512-1517. This looked at the
performance of the software in a clinical screening programme (62
citations).
[4] Scotland GS, McNamee P, Philip S, et al. (2007). Cost-effectiveness
of implementing
automated grading within the national screening programme for diabetic
retinopathy in Scotland.
Br J Ophthalmol, 91: 1518-1523. This assessed the
cost-effectiveness of the software and was a
companion paper to 4 (30 citations).
[5] Scotland GS, McNamee P, Fleming AD et al. (2010). Costs and
consequences of automated
algorithms versus manual grading for the detection of referable diabetic
retinopathy. Br J
Ophthalmol, 94: 712-719. This extended the number of clinical
features that the software could
detect to look at its ability to detect referable retinal eye disease,
i.e. that which is at an advanced
stage.
Relevant Grant Funding:
• 1995-1997: £388,644, NHS HTA Programme. The value of digital imaging in
diabetic
retinopathy. PF Sharp, JV Forrester, A Grant.
• 2003-2005: £220,854, Chief Scientist Office. SEHD. The role of
automated grading of
diabetic retinopathy in a primary care screening programme. JA Olson, PF
Sharp, P
McNamee, G Prescott.
• 2005-2007: £183,743, Chief Scientist Office. SEHD. The role of
automated level two
grading within the Diabetic Retinopathy Screening Collaborative Network.
JA Olson, PF
Sharp, K Goatman, A Fleming, P McNamee, G Prescott, S Philip, G Williams,
G Leese, K
Swa, M Virdi, W Wykes.
• 2008 -2012: £432,174, NIHR HTA Programme Improving the value of
screening for
diabetic macular oedema using surrogate photographic markers. JA Olson, PF
Sharp, K
Goatman, G Scotland, P McNamee, G Prescott, S Philip, K Swa, R Newsom.
• 2010-2013: £232,460, Medalytix Ltd. Salary support for research fellow
for 3 years. PF
Sharp.
• 2011-2012: £25,992, Chief Scientists Office, SGHD The contribution of
automated
retinopathy grading to predicting 5-year cardiovascular disease risk in
people with
diabetes in Scotland. A Fleming, S Philip, G Prescott, JA Olson, PF Sharp,
K Goatman.
• 2012-2014: £179,617, Chief Scientists Office, SGHD Can automated
analysis of
sequential retinal images of people attending diabetic retinal screening
predict future
referral to Ophthalmology? S Philip, JA Olson, PF Sharp, G Prescott.
Details of the impact
The research carried out at Aberdeen has improved the quality and
cost-effectiveness of
screening for diabetic retinopathy and has been central to the enhancement
of Scotland's national
screening programme. Thus, it has achieved a significant impact on patient
health and welfare,
as well as economic impacts for the taxpayer, through cost savings for NHS
Scotland, and for the
company that developed the screening software commercially.
In 2006, the research team was approached by a new start-up company,
Medalytix [a]. The
team, supported by Scottish Health Innovations [b], negotiated a licence
agreement with
Medalytix on the automated grading software. Following a number of further
licence agreements
and patents, and a £2 million investment package from (amongst others) the
business-venture
arm of the Spanish National Organisation for the Blind, the company
developed a commercial
version of the software known as iGrading. This, according to a 2010/11
report by Scotland's
Diabetic Retinopathy Screening Programme [c], was successfully piloted. In
2012, Medalytix
agreed a sub-licence with Digital Healthcare to market the product.
Medalytix's current sales
figures are not known, but a condition of the licensing was that the
products should be made
available to the Scottish screening service free of charge. Thus not only
has industry benefitted,
but NHS Scotland has had free use of the software.
Following a 2009 independent review by the Scottish Diabetic Retinopathy
Screening
collaborative (made up of individuals from all NHS Boards in Scotland) on
behalf of the Scottish
Government, it was recommended that "automated grading should replace
level 1 manual grading
in Scotland." This recommendation was implemented in 2010, with the result
that the Scottish
Diabetic Retinopathy Screening Service's screening centres now use the
automated software
developed by the Aberdeen research team. The workload of screeners has
been reduced by
nearly 40% through the new method, and the estimated annual cost saving
for NHS Scotland is
around £200,000 per year.
Since 2008, interest in using the software has also been shown by centres
in other parts of the
UK, Europe, South America, Africa and Australia. The Aberdeen team has
worked actively to
increase awareness and understanding of diabetic retinopathy and the case
for automated
screening among clinicians, professional and interest groups, and the
general public. In 2010 the
team presented details of its findings to medical ophthalmologists at the
World Congress of
Ophthalmology in Berlin and to retinal screeners at the British
Association of Retinal Screeners'
annual general meeting. In 2012, as part of the University's outreach
programme, they explained
the details and implications of their work to the general public through
the University's series of
informal public talks (the Café Med series).
A review of NHS Screening Services in NHS Scotland in 2012 by Deloitte
(currently private and
confidential) concludes that autograding is proving to be as effective as
level-1 graders. It notes
that as the diabetes population is increasing (4-5% per annum) automated
grading will be
invaluable in processing the increasing volume of images.
The National Collaborative Coordinator for the Scottish Diabetic
Retinopathy Screening (DRS)
Service has confirmed: "Without the research and development of this
software, undertaken by
Aberdeen University the programme would have no option but to continue to
manually grade
patient's photographs....DRS patients require to be screened for diabetic
retinopathy annually
and with the growing numbers the automated grader system will be an
essential asset in helping
the NHS in Scotland to continue to provide a high quality screening
programme for all eligible
patients with diabetes in an efficient and effective manner [f].
The research findings have reached non-specialist audiences through the
pages of the Aberdeen
Press and Journal and the Aberdeen Evening Express (January 2008,
combined circulation over
110,000). The blog, Diabetic Retinopathy News [d], explained the
system of automated grading
and the reduction in workload it achieves through an article in October
2011, which is still
available online. Further coverage appeared in the professional journal, The
Engineer (March
2009, circulation over 30,000), whose website also retains it [e].
Sources to corroborate the impact
[a] Medalytix Company Web site (http://www.medalytix.com/).
Explains the application of the
product to the national screening programme and its clinical validation
of the technology in a live
screening programme and availability for use.
[b] Scottish Health Innovations Ltd, I-Grading Software description
(http://www.shil.co.uk/Products/igradingtm-platform-diabetic-retinopathy-screening-software.html)
— detailed description of the technology and its developmental
background, and its central role in
the national screening programme.
[c] The National Diabetic Retinopathy Screening Programme, Scotland
(http://www.ndrs.scot.nhs.uk/).
In the 2010/11 report the Lead Clinician states "We have been
piloting an automated-grading system in NHS Grampian for the last year.
...... We have now just
started work to provide a national version for Scotland using a
centrally hosted model. All NHS
Boards will be able to access this automated grading system. We are
confident that it will
contribute to national efficiency savings despite of increasing demands
from a rising diabetic
population."
[d] Diabetic Retinopathy News — describes the use of I-grading and
reduction in workload
(http://www.diabetic-retinopathy.org/2011/10/automated-grading-of-digital-retinal.html).
Highlights
the reduction in workload of manual graders by 38% using the software
and its accuracy in the
national diabetic retinopathy screening programme of 93% to 100%
depending on the severity of
the changes.
[e] The Engineer (http://www.theengineer.co.uk/news/software-scans-retinas/310559.article)
Explanation of product, its importance and the company has acquired £2M
of European
Investment through ONCE (business arm of Spanish National Organisation
for the Blind) to
market internationally and benefit countries where there is insufficient
screening infrastructure
emphasised.
Testimonials:
[f] National Collaborative Coordinator for Diabetic Retinal Screening
[g] Lead Author of independent review for Scottish Diabetic Retinopathy
Screening Collaborative
[h] Director, National Services Division, NHS Scotland
[i] Senior Manager, Scottish Health Innovations Ltd., NHS Scotland