Research still has a very important role to play in blindness prevention both in developed and developing countries. It remains an essential requirement to inform and improve eye health program designs, to evaluate these programs and to effectively advocate blindness prevention to governments and legislators. The following article discusses specific areas of blindness prevention that require research and argues that it will continue to play a crucial role in the fight to eliminate avoidable blindness by the year 2020.
More than two thirds of global blindness is preventable or treatable and about half of those who are blind have lost their vision due to cataract. We know what to do about cataract and we know a lot about how to treat most of the other main causes of blindness and visual impairment in the world. So why do we still need to conduct more research and shouldn’t we just now get on with the job of eliminating avoidable blindness?
Evaluative and Impact Research
Vision 2020 The Right to Sight is the global initiative for the elimination of avoidable blindness. In 2009, in an important push towards reaching the goals of Vision 2020, the 62nd World Health Assembly endorsed the WHO Action Plan for the Prevention of Avoidable Blindness and Visual Impairment. One main objective of the Action Plan is to increase and expand research for the prevention of blindness and visual impairment. Special emphasis should be placed on the evaluation of interventions and different strategies for early detection of eye diseases in different populations.
Diagnosis is complex and treatment options common in high income countries are not practical or affordable in low income countries
The Action Plan specifically identifies the following research priorities:
- Socioeconomic determinants of blindness and visual impairment
- Role of gender in blindness prevention
- Cost-effectiveness of interventions
- Identification of high-risk population groups
- Economic cost of blindness and visual impairment and its impact on socioeconomic development
Research to inform and improve programs
Surveys
Changes in the world’s population have impacted upon the prevalence, main causes of and distribution of blindness and visual impairment. We know that the role of communicable diseases like measles or onchocerciasis as a cause of blindness is decreasing, while age-related non-communicable causes of blindness are on the rise, e.g. glaucoma and diabetic retinopathy.
Population-based surveys can give estimates about the extent of the problem and the pattern of causes in different regions of the world. This helps us set targets such as cataract surgery numbers and priorities for interventions; e.g. should we use available funds to focus on early detection of diabetic retinopathy or on training of refractionists?
In the past, surveys have used different definitions and methods, making direct comparison between regions or countries difficult or even impossible. Only since the development of standardised methodologies such as the Rapid Assessment of Avoidable Blindness (RAAB) by the World Health Organisation (WHO), are we able to assess geographical differences in the prevalence of blindness. This often yields very interesting results, including the scope of difference in the prevalence of blindness within a country or a region. For example, we now know that the prevalence of blindness in parts of Eastern Africa is five times lower compared to the Horn of Africa, requiring different approaches to reaching Vision 2020 targets in either region. So far, surveys have been carried out in 65 countries. The lack of data in the remaining countries is slowing down planning, monitoring and evaluation of blindness prevention programs.
Disease Control
‘Disease control’ is a very broad term, but here it refers to the research into improving the way blinding eye diseases are being diagnosed and treated. In recent times we have made good progress in delivering quality cataract surgery in resource poor settings. The main challenge now is to deliver quality cataract surgery in an economically sustainable way.
As is occurring in high income countries, patients from low income countries are increasingly demanding cataract surgery at an early stage of the disease, particularly patients in urban areas. Research is required to better understand the consequence of increasingly treating non-blinding cataracts while aiming to reach the Vision 2020 target of eliminating cataract blindness. For a long time, improving cataract services within blindness prevention programs was all about increasing numbers. It is crucial to improve our focus on the quality of surgical outcomes.
Uncorrected or under-corrected refractive error is receiving increased attention and recognition as a main cause of visual impairment and often blindness. The problem is exacerbated in low income countries due to a lack of available services and the prohibitive cost of eyeglasses. However, great improvements have been made in the development of protocols for the education, training and certification of spectacle providers in low income countries.
In the short term, data on the prevalence and types of refractive error among different populations and age groups in low income countries is required. Research towards the cost-benefit and cost-effectiveness of spectacle supply in low income countries would help to explore the economic impact of refractive error correction and its effect on education. In the long term, research might be applied into the application of new treatment technologies such as laser correction in these countries.
While screening and treatment options for cataract, refractive error or even trachoma are comparatively well established, other main causes of vision loss in low income countries require increased research efforts. For instance, we are pretty lost when it comes to blindness that is due to glaucoma. Diagnosis is complex and treatment options common in high income countries are not practical or affordable in low income countries, e.g. long term treatment with medication. Thus, there is an urgent need for research into screening and treatment options suitable for low income countries.
The term ‘epidemic’ is commonly used to describe the increase in diabetes in the world, especially in low income countries. Diabetic retinopathy is one of the main complications associated with diabetes mellitus. Although treatment with the right skills and equipment is highly successful, cases need to be detected early to prevent blindness. Research efforts need to focus on early screening options including new technology that is affordable and suitable for screening in hot and dusty conditions.
To sum up, emphasis should be given to early detection of the causes of blindness and visual impairment, but also to the evaluation of interventions and strategies. Programs to prevent blindness and visual impairment need to be evidence-based and cost-effective. We need better mechanisms for monitoring and evaluation across all levels of activities to be able to demonstrate the progress and impact of blindness prevention programs within the Vision 2020 initiative. Lack of such evidence diminishes the chances of much needed long term support from donor supporters and governments.
The Action Plan further proposes to international partners of Vision 2020 to support low and middle income countries in building their own eye research capacity required for program implementation and evaluation. National research institutions that are involved in prevention of blindness and visual impairment related research should be supported; i.e. research capacity should be developed in a sustainable manner.
The endorsement of the Vision 2020 Action Plan means that clear research objectives are being recommended by The World Health Assembly to all member states of the initiative and international partners. Standardised objectives support a more coordinated approach towards research among academic institutes, non-government organisations (NGOs) and other partners, which would optimise the impact we can achieve with our limited resources.
At the same time, research is only worth carrying out if outcomes are actually being translated into action on the ground. Publishing outcomes in peer reviewed journals can only be the beginning of making use of quality research. The real challenge is to translate research outcomes into practical changes that improve our work in the field. With their access to patients and decision makers in the countries they work in, this is where eye NGOs can really play a vital role in blindness prevention.
