Prof Kovin Naidoo
Intro: I am Kovin Naidoo, the CEO of the Brien Holden Vision Institute [Edit: Kovin stepped down from the Chair of IAPB Africa by the end of 2016]
I think the paper, or rather, the research collaboration that had the biggest impact on my life is the Refractive Error studies in children which was led by Leon Ellwein and was aimed at a global collaboration that was bringing together population based studies so that we can accurately understand the prevalence of refractive error in children. It led to us having the kind of projections we have now where we use between 3 and 5 % in planning etc. in terms of prevalence for Africa. We know it led to the data that showed us that huge increase in prevalence in China in comparison to the rest of the world and they became great advocacy tools not just within those countries but also at the level of the WHO and influence.
But what was good about that group of scientists was they were very realistic. We knew that we really suffered to do those studies, you know, visiting, went to every home, the cost of those studies were just enormous. Also the rigor we had in terms of the science, we wanted to maintain that but try to reduce the cost.
Leon Ellwein in particular was amazing in making sure that we all learned everything that we needed to during that process… that we adhered to the systems etc.
Screen: Paper One: Global Magnitude of visual impairment caused by uncorrected refractive error in 2004
Screenshot of paper
We didn’t have a global figure for adult and children uncorrected refractive error and in terms of blindness and visual impairment due to uncorrected refractive error and that data was absolutely critical in order to convince the WHO to prioritize uncorrected refractive error. Resnikoff et al in their paper then quantified it at 185 million people in the world who are blind or visually impaired because of uncorrected refractive error and that paper really became a major advocacy tool. And I think it influenced a lot of the gains that we got around uncorrected refractive error.
It got a great profile, it took…it gave people across the globe a single figure that we could now talk about.
Screen: Paper 2 Potential lost productivity resulting from the global burden of uncorrected refractive error
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Paper 3 Global vision impairment due to uncorrected presbyopia screenshot of paper
However, the challenge was until that point there was very little talk about two aspects. Firstly the issue of the impact of uncorrected refractive error and mainly the economic impact because there hadn’t been much other studies that you could do a meta analysis and put data together so that was the one issue. Secondly, there was increasingly a view that you can’t talk about uncorrected refractive error and don’t talk about presbyopia. So two things happened, the first paper with Fricke et al, I was a part of the group that did the study where we showed that the lost productivity due to uncorrected refractive error was 269 billion $.
The next thing we did was we said we need to look at presbyopia so then there was the paper on the global prevalence of presbyopia where we quantified that presbyopia has 517 million people who are blind or visually impaired due to presbyopia and combining those two numbers we now had a number for uncorrected refractive error which was distant and we now had a number for presbyopia.
Screen: Global Vision Impairment due to uncorrected presbyopia
Screen: Paper 4 Global cost of correcting visual impairment from uncorrected refractive error
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Demand on our scientists is not only to talk about the problem but also to come up with indications as to firstly how we can solve it and what the cost is. There have been lots of studies on vision centers particularly the work Nag Rao and team have done out of India (referring to LV Prasad Eye Institute in Hyderabad, India) or Aravind (Aravind Eye Care System) out of India. There was a paper that we published in South Africa that showed how refractive error can be integrated within a district health system. The data there showed that you could reach more than 1.3 million people, expand your Human Resources and create a sustainable output from that system. But what was missing was what is this going to cost? And so we set out to conduct a study to show what is the global cost of addressing the 158 million that Resnikoff et al had spoken about and in that respect we came up with a figure of 28 billion, to train, to setup infrastructure etc And we juxtaposed that with the 269 billion $ of lost productivity in terms of international dollars or 202 million $ whichever one you want to use that it was a great investment that the science was showing us to setup refractive services.
Screen: Paper 5 The global burden of potential productivity loss from uncorrected presbyopia
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Then in the whole continuum of research that was occurring there was a major gap around the lost productivity due to uncorrected presbyopia and as you know that we had put the number on the table around uncorrected refractive error and we came up with a figure of 11 billion. Now I must admit that the lost productivity studies around presbyopia was much tougher for us because there were very few studies available, population-based studies available. Fortunately steps in again Leon Ellwein with the NEI-WHO collaboration and we conducted these global presbyopia studies which again quantified presbyopia in specific areas to a population based study.
It is an issue that resonates beyond the scientific community, beyond the eye care community, its industry is very keen on it. We are conducting a study among clothing workers to look at the productivity lost due to presbyopia and there is some interesting data emerging out of the preliminary analysis.
Screen: Paper 6 Prevalence and causes of vision loss in sub-Saharan Africa: 1990 – 2010
Screenshot of paper
The Global Burden of Disease collaboration, which I think, has just added a whole new dimension to epidemiological research. It’s gained a lot of support but under the leadership of Rupert Bourne there is a group of us that have come together as the Vision Loss Expert Group and through that process have now been working on building the prevalence database, doing meta-analysis and coming up not just around vision impairment and blindness but around uncorrected refractive error, glaucoma, diabetes, all series of papers have been established. But what has been great about that is the openness of the collaboration and thus far I have been talking about scientific projects with close teams working on it. The Global Burden of Disease study has just opened up the process.
I was privileged in this global burden of disease study to be the lead author on the African prevalence of blindness and vision impairment and I am sure others will talk about the prevalence in other regions but in Africa between 1990 and 2010 we showed that the reduction in blindness, in prevalence from 1.3 to 1.1 % and vision impairment from 5.3 % to 4% between 1990 and 2010. And this was good data, strong advocacy tool because we can say that efforts are leading to change, exactly who is making the change and how is a great research question and I think that one of things we have to start to do is really looking at issues outside prevalence and for that reason we are doing a lot of impact studies now, trying to look at issues that give us evidence so as to why this is happening and whether it is happening.