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

Screening

What are the risks?

Are the risks changing?

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

OCT photographic clinics for screen test positive 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)

Agreement against system & peers

April, Screen no.7‘System’ grade

Grader 23 -

Agreement against system & peers

April, Screen no.8

‘System’ grade

Grader 23 -

Screening Programme – why does it matter?

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

Diabetic Retinopathy Screening

How to Start

Buy a Fundus Camera?

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 test – number of fields and positioning

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

Management of patients with ungradable images

Clear protocols need to be in place

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.

Thank you for listening

It is worth doing despite all the obstacles and organisational difficulties!