Abstract
Purpose :
To explore trends and the relationship between the prevalence of blindness and national income levels globally over time.
Methods :
Data on the population prevalence of blindness, defined as a visual acuity of ≤ 3/60, for all causes, for all ages and genders was analyzed by national income levels as measured by Gross Domestic Product (GDP) per capita income for 157 countries for which complete matching data sets were available over the period 1990-2015 in 5-year bands. GDP per capita was measured in constant 2010 US$. Income levels were stratified into low, middle and high-income economies according to World Bank criteria. The correlation coefficients between the prevalence of blindness and level of income were calculated using Excel.
Results :
Two significant trends were observed, namely rising national income levels and decreasing levels of blindness globally (p<0.05). There was a trend towards a decrease in the total number of low income countries from 41 in 1990 to 28 in 2015 and an increase in the number of high income countries from 34 in 1990 to 44 in 2015 suggestive of global economic growth. The prevalence of blindness globally also decreased over the same period from 0.75% in 1990 to 0.48% in 2015 (P<0.05). Overall, the prevalence of blindness and national income levels were not found to be correlated for low and middle-income countries, however, they were significantly correlated for high income countries (Correlation coefficients range: 0.39 to 0.47) and globally (Correlation coefficients range: 0.45 to 0.49) both (p<0.050) though rising incomes alone did not explain all of the observed correlation.
Conclusions :
Globally, there was a trend towards rising national income levels and a decrease in the prevalence of blindness. Both blindness and national income levels were found to be highly correlated for high income countries and globally, but not for low and middle-income countries. There was an overall trend towards a reduction in the number of low income countries and an increase in the number of high income countries as well as a decrease in the prevalence of blindness over time. Continued economic growth and development is an important strategy to encourage income growth in low and middle-income countries which, in turn, maybe used to fund sustained long-term reductions in the prevalence of blindness.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.