lessons from the uk national dr screening program for areas with limited resources prof. peter...
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Lessons from the UK National DR Screening Program for Areas with Limited Resources
Prof. Peter Scanlon MD FRCOphth FRCP DCH
Programme Director
English National Programme
UK Population
Northern Ireland - population 1.8 million
England - population 51.9 million
2.6 million with diabetes
Scotland -population 5.2 million
Wales- population 3.0 million
2011-12
81 centres
2.6 million with diabetes
2.4 million offered
1.9 million actually screened
Increase 121,000 in 12 months
English National DR Screening Programme
Large Telemedicine Programme
Cost approx 80 million US dollars
Basis of the ENSPDR Grading Criteria
Fundus photographic risk factors for progression of diabetic retinopathy. ETDRS report number 12. Early Treatment Diabetic Retinopathy Study Research Group. Ophthalmology 1991; 98:823-33.
ETDRS final Retinopathy Severity Scale
ETDRS(Final)Grade
Lesions Risk of progression to PDR in 1 year(ETDRS Interim)
ETDRS follow up intervals English Screening Programme levels3
No apparent retinopathy
1014, 15
DR absentDR questionable
R0 Currently screen Annually
Mild NPDR 20 Micro aneurysms only 1 year R1 Screen annuallyBackgroundmicroaneurysm(s) Retinal haemorrhage(s) any exudate venous loop
35abcde
One or more of the following:Venous loops > definite in 1 fieldSE, IRMA, or VB questionableRetinal haemorrhages present HE > definite in 1 fieldSE > definite in 1 field
Level 30 = 6.2%4-6 months
Moderate NPDR 43ab
H/Ma moderate in 4-5 fields or severe in 1 field orIRMA definite in 1-3 fields
Level 41 = 11.3%3-6 months
R2 Refer to ophthalmologistPre-proliferative venous beading or reduplication intraretinal microvascular abnormality (IRMA) multiple blot haemorrhages
Moderately severe NPDR
47abcd
Both level 43 characteristics – H/Ma moderate in 4-5 fields or severe in 1 field and IRMA definite in 1-3 fieldsor any one of the following:IRMA in 4-5 fieldsHMA severe in 2-3 fieldsVB definite in 1 field
Level 45 = 20.7%4 months
Severe NPDR 53abcd
One or more of the following:> 2 of the 3 level 47 characteristicsH/Ma severe in 4-5 fieldsIRMA > moderate in 1 fieldVB > definite in 2-3 fields
Level 51 = 44.2%Level 55 = 54.8% 3 months
Mild PDR 61ab
FPD or FPE present with NVD absent or NVE = definite
R3 ProliferativeUrgent referral to ophthalmologist
Key points – refer at 11.3% risk of developing proliferative in 12 monthsR1 = background = mild NPDR = do not referR2 = pre-proliferative = moderate to severe NPDR = referR3 = proliferative = refer
Year of diagnosis of diabetes
1922–59
1960–69
1970–74
1975–80
WESDR: Twenty-Five Year Progression Of Retinopathy In Patients With T1DMBetter glycaemic control and to a
lesser extent BP control may be
beneficial in reducing incidence of
PDR and increasing odds of
improvement of DR
Reduction in prevalence of PDR in
more recently diagnosed cohorts
possible benefit of recent
changes in management of
diabetes
Klein, R et al. Ophthalmol. 2008; 115:1859–1868WESDR; Wisconsin Epidemiologic Study of Diabetic Retinopathy
70
60
50
40
30
20
10
0
PD
R P
reva
len
ce (
%)
Duration of Diabetes (years)
0–4 5–9 10–14 15–19 20–24 25–2930–3435+
Maculopathy
•M0 No maculopathy
• M1 Maculopathy •exudate within 1 disc diameter (DD) of the centre of the fovea
29% thickening (Birmingham P Dodson personal communication)
•group of exudates within the macula
Did not find CSMO if <1DD Mr N Dhingra, Wakefield UK
•any microaneurysm or haemorrhage within 1DD of the centre of the fovea only if associated with a best VA of 6/12 (if no stereo)
14% thickening(Birmingham P Dodson personal communication)
What are the risks of developing Clinically Significant Macular Oedema from 2D photographic markers?
Key points – M0 = No maculopathyM1 = Maculopathy
Standardising the grading of retinopathy
In 2009/10, English DESP introduced:
Monthly QA test sets for all (1500+) graders in 86 local screening sites
Sets of 30 (Yr 1) or 20 (Yr 2) cases / month, weighted to DR+ cases
Year 1: Up to 12 blocks in numerical order
Year 2: Up to 12 ‘monthly’ sets
Accessed via the internet
Accessed via the internet at their own place of work or from home
Not referred:11/157 (7.0%)
Exact:235/300 (79%)
Exact agreement with R + M grade: Yr 1M
ean
pro
po
rtio
n (
%)
agre
emen
t w
ith
sys
tem
gra
de
Block number Yr 1 (2009-10)
1301 1278 1235 1112 1003 948 901 827 731 664 564 461
Number of Users completing all cumulative blocks -
Trend: p<0.001
Exact agreement with R + M grade: Yr 2M
ean
pro
po
rtio
n (
%)
agre
emen
t w
ith
sys
tem
gra
de
Monthly sets Yr 2 (2011-12)
780 886 957 865 940 882 (0) 1016 896 1011 931 952
Number of Users completing set in month -
Trend: p<0.01
N.B. No test was presented in October 2011
Mean (SD)
Generic QA Themes & Objectives
Theme Objective
1. Identify cohort To maximise offer of screening to all eligible population
2. Inform To maximise informed choice throughout screening programme
3. Invite In those who want screening, to facilitate uptake in eligible population
4. Test To maximise accuracy of screening test
5. Minimising harm To minimise potential harms from screening
6. Diagnose To ensure accurate diagnosis
7. Intervene/ Treat To ensure high quality and timely intervention
8. Outcome To optimise public health and individual outcomes in target population
9. Staff To ensure that whole screening programme is provided by a trained and competent workforce
10. Commissioning and governance To ensure effective commissioning and good governance of the screening programme
11. User experience/patient journey
To ensure a high quality journey throughout the screening process
12. Equality To ensure that screening programmes fulfil their requirements to reduce health inequalities
Step 1. Manoeuvring around the politics of funding
Many different levels
Who is going to provided funding to support
Is this going to be run by Public Health Physicians or by Specialists – Diabetologist? Or
Ophthalmologist?
A Champion is needed who has some skills in diplomacy
Budgets need to be ring fenced
Politics change from when a service is getting off the ground to when it is up and running
European Experience - barriers
Public awareness
Patient compliance
Lack of funding for equipment, training, education
Collaboration between ophthalmologists and diabetologists
Lack of engagement of private providers of eye care
Lack of systematic process, competency, registers, data
Political instability
Access to laser treatment remained poor in a few countries. Some perverse financial incentives
were reported causing for example intravitreal bevacizumab or triamcinolone being given
even when laser is available.
Step 2: Are Assessment and Treatment facilities available?
Adequate number of lasers and ophthalmologists to
treat
If not - Contract with an organisation that can provide
treatment
Step 3. Identify cohort for invitation and call - recall
Diabetes Register
How do you record patient details?
If literacy levels are low the patient surname may be spelled
differently at each visit
Is there a National ID number?
Are births and deaths recorded in the population?
Step 4. How are you going to invite them?
Letter?
Word of mouth?
Etc………..
In those who want screening, to facilitate uptake in eligible population
Step 5. How are you going to inform the patients and maximise uptake?
To maximise informed choice throughout the screening programme
1. Educating the population - this is not a diagnostic test – some patients with sight threatening
diabetic retinopathy will be missed.
2. Patient education, engagement with patient organisations,
3. Appropriate exclusion criteria
e.g. those already under ophthalmology, terminally ill etc..
Step 6. Establish an IT infrastructure
Preferably as simple as possible
Need reliable power supply
An inexpensive joined up solution for administration of
call recall, screening, grading and audit is an urgent
requirement.
Make sure images attached to patient details
Who is going to support that IT iinfrastructure?How is it going to be backed up?How are you going to ensure confidentiality of patient data?
Step 7 - Purchase a Camera
Minimum camera specification
Most of the modern non-mydriatic digital cameras meet a good quality specification
What relationship is there with the camera manufacturer for technical support in your area?
Image sizes of cameras and recommend compression at source
Output resolution
Output Resolution in
millions of pixels
Uncompressed File size in MB
12:1 Compression
in KB
20:1 Compression
in KBCamera Back H V
Nidek NM-1000 integral 1360 1024 1.39 4.2MB 348KB 209KB
Kowa Non-Myd alpha integral 1600 1216 1.95 5.8MB 486KB 292KB
Topcon NW100 integral 1792 1184 2.12. 6.4MB 530KB 318KB
Topcon NW6 Nikon D1H 2000 1312 2.62 7.9MB 656KB 394KB
Nikon D1x 3008 1960 5.90 17.7MB 1.47MB 884KB
Nikon D1x 2000 1312 2.62 7.9MB 656KB 394KB
Canon CR6/DGi Canon EOS 10D 3072 2048 6.29 18.9MB 1.57MB 944KB
Canon EOS 10D 2048 1360 2.79 8.4MB 696KB 418KB
D30 2160 1440 3.11 9.3MB 778KB 467KB
Step 8 - The test and grading images – Choices for programmes
1.Mydriasis or non-mydriasis?
2.The number of fields
3.The grading referral criteria
4.Viewing the images for grading
The test – mydriasis, selective mydriasis or not?
11.3%
36.4%
0.0% 1.4% 1.2% 0.8%
4.8%2.0%
68.2%
40.1%
26.2%
16.5%
11.0%
5.3%
0.0%
5.6% 6.3%
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
80.0%
16-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89 90+
Age Group
Unassessable image patients for mydriatic (Total 133/3611 =3.7%) Unassessable image patients for non-mydriatic (Total 711/3604 =19.7%)
Clear protocols need to be in place
The Grading Referral Criteria
Recommend R0M0, R1M0, R1M1 etc…. So that every eye has at least an R and M gradeThis makes it much easier to compare between programmes
Retinopathy progresses with increasing ischaemia
R grade
Leaks occur in the macular areaM grade
The treated patient is more difficult to grade
Recommendations on Viewing Images
1. Screen resolution
2. Display 60% of the image at once on the grading screen
Step 9.Employ and train a competent workforce
To ensure that whole screening programme is provided by a trained and competent workforce
1.Staff accreditation
2.Evidence of ongoing CPD and EQA test sets
Step 10. introduce some Quality Assurance
1. Reduce the probability of error and risk
2. Ensure that errors are dealt with competently and sensitively
3. Help professionals and organisations improve year on year
4. Set and keep under review national standards;
5. Manage these processes.
1. What would I do with 150k USD recurring?
• Start with a pilot project
• Check that assessment and laser treatment facilities in place
• Liaise with local patient groups, ophthalmologists and diabetologists
• Write protocols and decide on patient pathways for screen positive
and ungradable images
• Make sure adequate power supply to screening and grading locations
• Employ someone with IT skills
• Choose software, hardware and back up facilities
2. What would I do with 150k USD recurring?
• Decide on grading form that refers at the agreed level of risk
• Train non medical graders
• Buy a camera
• Provide patients with appropriate education
• Invite cohort for screening
• Photograph eyes
• Send image to central grading where possible.
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