What do we mean by evidence-based programming?

We use evidence-based approaches in our programmes, and don’t shy away from doing things differently if it gets us closer to ending avoidable blindness.

Evidence-based programming means that we develop intervention programmes based on a community’s needs, as identified in rigorous, valid scientific research — not randomly. One valuable source of evidence to inform eye care programme design is the Rapid Assessment of Avoidable Blindness or 'RAAB'.

A RAAB is a population-based survey that gives the prevalence and primary causes of blindness and visual impairment, the quality of eye care services, barriers, cataract surgical coverage and other indicators of eye care services in a given country. Sometimes a RAAB also includes a component that helps to assess the prevalence of diabetes and diabetic retinopathy (DR), which pose an increasing threat, particularly in urban areas.

It’s called “rapid” because the survey can be carried out in as little as five to six weeks, and is not designed to be a detailed blindness survey or case-finding exercise. Rather, it provides reasonably accurate estimates of the prevalence of blindness in adults aged 50 plus years, and the proportion that is avoidable. Because it only includes the over-50 age group, where the prevalence of blindness is highest, so that sample size requirements are reduced. 

It is not designed to be a detailed blindness survey or case-finding exercise. Rather it uses simple sampling and examination techniques to provide reasonably accurate estimates of the prevalence of blindness and the proportion that is avoidable. RAAB is also relatively cheap because it can be carried out quickly, does not need expensive ophthalmic equipment, and can be conducted out by local staff.

With the support of Brien Holden Vision Institute (BHVI) and funding from The Fred Hollows Foundation, the first-ever RAAB was conducted in 2017 in Papua New Guinea (PNG), an ecologically and culturally rich country with a population of over 7.6 million people.

Collecting data in PNG is a challenge, let alone collecting it rapidly, owing to rugged terrain, poor transport infrastructure, and recurrent law and order problems.

Nevertheless, with the support of the National Prevention of Blindness (NPBL) Committee, the survey went ahead. Some 4,818 adults aged 50+ years from 100 randomly selected communities had their vision examined as part of the survey. In the National Capital District (NCD), diabetes and DR was also assessed.

The data revealed significant eye health challenges.

Across all regions in PNG, the rate of blindness was found to be 5.6 percent, up from 3.9 percent in 2005. This equates to over 40,746 people who are blind in both eyes, and almost 67,987 who are blind in one eye. This is significantly higher than in neighbouring Pacific Islands, where the prevalence of blindness ranges between 0.5 percent and 4.2 percent. The main cause in PNG is untreated cataract, accounting for 89 percent of all blindness. Some 61 percent of all blindness was found to be experienced by women. Approximately two-thirds of all participants who needed spectacles were found to not have them. The RAAB also revealed that in the NCD alone, 7.8 percent of all adults aged 50 plus years had diabetes. Of these, almost half had some form of diabetic retinopathy (DR) or maculopathy.

There are tens of thousands of people in the country who are needlessly blind, mainly due to untreated cataract. These results highlight the urgent need for all stakeholders to continue working together to increase people’s access to specialist eye health services and technology.

Over the last 11 years, we've worked with local eye care and health organisations, the National Department of Health, and provincial health authorities to design and implement an approach to tackling avoidable blindness. This has included training the Papua New Guinean health workforce in eye care and supporting them to deliver high-quality eye care to their communities, mostly through outreaches and our eye clinic based in Madang.

We have the evidence. We won’t stop until our job is done.