Key learning points
A diabetic retinopathy (DR) programme involves more than finding patients at risk
of DR. There must be agreed guidelines on who should be examined, referred, or treated.
An accurate register of patients with diabetes is essential, and may be difficult
to develop.
Retinal examination methods should be accurate, cost-effective, and cause minimal
inconvenience for the patient. Both retinal photography and retinal examination by
an ophthalmologist are accurate, but photography may be more cost-effective in the
long-term.
A referral network is essential so that any patient with diabetes found to have severe
retinopathy is guaranteed to receive laser treatment if required.
Ophthalmologists should work closely with physicians and others to ensure that all
patients receive appropriate eye care, and diabetes management, to prevent blindness.
The World Health Organization encourages the promotion and development of programmes
for the prevention, detection, and management of diabetic retinopathy (DR). Such programmes
must identify effective strategies and technology so that they can be adapted to the
situation in each part of the world. Programmes must also be monitored and continuously
improved.
The guidelines discussed in this article were developed by experts brought together
during workshops hosted by the VISION 2020 Latin America technical subcommittee on
DR and technical support was provided by the Pan-American Asociation of Ophthalmology
(PAAO). Although these guidelines have been developed for Latin America, we hope that
the principles they contain will provide a good starting point for the planning of
DR services in other low- and middle-income countries.
Getting started
Before we start planning a DR programme, it is helpful to review where we are and
where we want to be:
What is the need for DR services (for prevention, diagnosis and treatment) in our
population?
What services and resources are required to meet this need?
What services and resources are already available, and where do these fall short of
the need?
Doing so will allow us to set goals and establish priorities for action.
A programme to manage DR should include the following:
A good understanding of the current and projected prevalence of DR, to make it possible
to plan services for prevention, screening, and treatment
Clinical guidelines with a simple classification system, recommended examination intervals,
and suggestions for treatment
A way of finding patients with diabetes and DR
Retinal examination methods that take into account available equipment and human resources
Creation or identification of laser treatment centres for timely treatment
An education and prevention programme that reaches the whole population
Advocacy to secure the support of the authorities, educators, general practitioners,
endocrinologists, and so on
Long-term sustainability, using cost recovery or subsidies (see article on page 17
for an example from India).
When examining people with diabetes, test their visual acuity before you examine their
retinas. MEXICO
Estimating prevalence
The prevalence of DR can be difficult to estimate, and few estimates have been made
in low- and middle-income countries. A survey methodology called RAAB+DR has been
developed to estimate the prevalence of DR in a population in a quick and affordable
way. RAAB+DR has been tested in Mexico, South Africa, and Saudi Arabia, and the results
and recommendations will be discussed in a future issue of this journal.
The prevalence of DR in Latin America was estimated in 1999. At the initiative of
the Pan-American Association of Ophthalmology, 7,715 patients with diabetes from 16
countries were assessed. The study found that 40.2% showed some degree of DR, that
17% needed treatment, and that, most worryingly, 35% had never before been examined
by an ophthalmologist. A recent population-based study in Mexico found that the prevalence
of diabetes in people aged 50 or over was 21%. A total of 39% of patients with diabetes
had some DR, 16% had diabetic maculopathy, and 8.6% had proliferative DR. Less than
half of those known to have diabetes had been advised to have an annual eye examination.
Developing clinical guidelines
It is important to have a simple, easy-to-use grading or classification system to
help standardise appropriate management, referral, treatment, and monitoring for patients
with diabetes. On page 12 of this issue, we have published one such system, based
on the international clinical disease severity scale for DR and diabetic macular oedema
as set out by the International Council of Ophthalmology (see Useful Resources on
page 23).
Finding patients with diabetes and DR
Ideally, there should be an effective information system that identifies people with
diabetes, calls them for screening, and records the outcomes of eye examinations and/or
referrals. In Latin America, because of its many fragmented health care systems, identifying
patients with diabetes for a national or regional screening programme poses a difficult
challenge.
Examining a patient's retina. MEXICO
Any screening programme requires clear referral criteria; only patients with retinopathy
meeting a pre-defined threshold should be referred to ophthalmologists. In addition,
there has to be some quality control to ensure that the screening programme is effective.
In areas where services are available, all patients diagnosed as having diabetes should
be examined. If that is not possible, we should consider concentrating on high-risk
groups, with priority given to people with type 1 diabetes, people aged 50 or over,
those with type 2 diabetes of more than ten years' duration, pregnant women with gestational
diabetes, and patients with nephropathy (which can be detected by testing for the
presence of albumen in the urine).
Retinal examinations
Yearly retinal examinations of all diabetes patients are necessary because the condition
is asymptomatic in its early stages, and because early treatment reduces both the
risk of blindness and the cost of treatment. Methods of detection include the following:
Retinal examination with a slit lamp and hand-held lens following pupil dilation.
This is the method with the greatest specificity (it does not tend to wrongly classify
someone who in fact does not have DR as having DR) and sensitivity (it does not tend
to miss DR in someone who in fact has it). However, it is time-consuming and hence
costly.
Taking one or two photographs of each eye with a non-mydriatic camera. This achieves
good sensitivity and specificity. Retinal photography with a digital fundus camera
is rapid and sensitive. Although the camera is expensive, it may reduce costs as only
patients with positive findings are referred to ophthalmologists. The photographs
can betaken by technicians, allowing ophthalmologists to examine the photographs of
large numbers of patients in a short time.
Using a direct or indirect ophthalmoscope. This has less sensitivity but is useful
when you do not have a slit lamp and lens.
‘Retinal examination methods should be accurate, cost-effective, and cause minimal
inconvenience for the patient’
Treatment
DR requires early treatment to slow or stop the progression of the disease. Improved
control of diabetes (page 4) is the most important, especially in patients with diabetic
macular oedema. Patients who have established sight-threatening retinopathy will require
laser treatment. Steroids and intravitreal anti-vasculuar endothelial growth factor
(anti-VEGF) therapy are used together with laser therapy for macular oedema. Vitrectomy
is indicated for non-clearing vitreous haemorrhage and tractional retinal detachment.
A workable DR programme must have the facilities, equipment, consumables, medicines,
and staff to provide all of the above.
Education and prevention
Education is a priority for the prevention of blindness due to diabetic retinopathy.
There must be clear messages for people with diabetes, their families, health workers,
and the general public, along the following lines:
DR is asymptomatic (it has no symptoms), and it carries a real risk of blindness.
With annual examination of the retina, early detection, and prompt laser treatment,
sight can normally be preserved.
Strict control of diabetes and blood pressure reduces the risk of retinopathy.
At the primary care level, education should focus on lifestyle and prevention of diabetes
by diet and exercise. At the secondary level, education should encourage better self-care
by patients, including improved control of blood sugar and blood pressure (see article
on page 4). Education should also promote regular eye examinations for all people
with diabetes.
Planning and advocacy
Effective lobbying or advocacy is essential. Advocacy is the act of arguing on behalf
of a particular cause, such as establishing a new DR programme, with the aim to influence
decision makers to support this cause. When planning an eye care programme, you should
aim to develop a solution that is appropriate to the local situation and that is directed
at the population with the greatest needs. Aim to ensure the greatest possible coverage,
quality of care, and sustainability in the long term.
Political will is needed in order to implement eye health policies, and this can be
generated by effective advocacy. Ideally, the eye care programme should be developed
by a working group in which everyone involved in the project is represented. This
group can identify any decision makers whose support will be required and invite them
to participate. The earlier the decision makers are involved in designing the solution,
the more likely they are to support the outcome and make helpful contributions. This
turns an obstacle (“How will we get their support?”) into an opportunity for collaboration.
‘Political will is needed in order to implement eye health policies, and this can
be generated by effective advocacy’
Any current inability to meet the existing demand for ophthalmological services is
fertile ground for promoting our DR programmes. In Latin America, we can deliver clear
messages to the health care authorities or legislators along the following lines:
Diabetes affects 7-10% of the population over the age of 20. Through screening, we
may find retinopathy in as much as 30% of patients with diabetes, and 5% of patients
with diabetes are likely to need laser treatment to reduce the risk of blindness.
Diabetes will be increasing in the future, and it is around twenty times cheaper to
treat it earlier rather than later.
Eye health plans should be directed toward helping the most vulnerable people so as
to achieve equal access to health care.
It is important to describe and publish the results of current and past prevention
of blindness programmes. Publishing in scientific journals helps to provide the evidence
you may need to convince decision makers. Persuading the media (newspapers, radio
and television) to then write and talk about this evidence creates public pressure
that will also persuade decision makers to act.
In Latin America, the epidemic of diabetes and DR poses such a great challenge to
the population's health that we cannot manage alone. Through the leadership of the
ophthalmology societies of Latin America, supranational bodies such as the Pan-American
Association of Ophthalmology (PAAO), and other organisations such as the Pan-American
Health Organization (PAHO) and the International Agency for the Prevention of Blindness
(IAPB), we can forge alliances with national governments. These alliances, when added
to the initiatives of non-governmental organisations, the ophthalmic industry, and
civil society, can greatly assist with the implementation of national plans for the
detection and control of DR.
Worldwide, any successful strategy to address DR will require close collaboration
among everyone concerned: ophthalmologists, endocrinologists, physicians, mid-level
eye care workers, outreach workers, pharmacists, public health specialists, community
leaders, politicians, diabetes patients, and the general public.
There is a lot to do, but together we can do it!
Finding diabetes patients: thinking beyond the eye clinic
We can do nothing about diabetes or diabetic retinopathy (DR) unless we know where
to find people who have diabetes.
Screening programmes are expensive, and countries with limited resources should not
attempt a national screening programme for DR; it would be too complex and expensive
to set up, administer, and manage.
It may be more cost-effective to work closely with our colleagues who see diabetes
patients during the course of their work, such as physicians, diabetologists, pharmacists,
and health insurers. We must encourage them to look for eye disease in their patients,
or at the very least to refer their patients for regular retinal examination (provided
that local treatment services are available).
We should also look for diabetes patients in our eye clinics, particularly those patients
with cataract, as cataract can be a consequence of diabetes. We must check patients'
blood sugar (if possible), carefully examine their eyes, and refer them for follow-up
and/or further investigation (see the table on page 12). We must also ensure that
they have access to a service to help them manage their diabetes.
However big or small our screening programmes, it is important to focus on more than
the clinical and technical aspects (such as camera vs. ophthalmoscope or technicians
vs. ophthalmologists). The biggest problems are administrative and managerial:
How do we identify the diabetes patients we want to examine?
How do we contact them to come for an examination?
What do we do if they don't turn up?
What do we do if a clear enough view of the retina is not possible?
How do we record the findings, and how do we share that information? With whom do
we share it, and when?
Where and how are patients referred?
How many of the people needing treatment actually attend and accept treatment after
referral?
What is the outcome of treatment?
In order for our screening to succeed, it is important to address these questions
as early as possible in any planning process.
Experiences in India
Dr Rajiv Raman and his colleagues in India have reported that only 54% of the general
practitioners or physicians they studied were aware of the need for annual retinal
examinations and referral for patients with diabetes. Just 1.3% used direct ophthalmoscopes
to detect DR, of which only half dilated patients' pupils before examination. The
barriers they faced were lack of time, lack of ophthalmoscopes and lack of training.
According to Dr Raman, diabetes patients in India also regularly visit their pharmacists.
Dr Raman recommends creating awareness among general practitioners and pharmacists
about their role in identifying and referring patients at risk of DR. General practitioners
could also be trained in the use of a direct ophthalmoscope as part of their continued
medical education or continued professional development.