Socio-economic disparity in visual impairment from cataract

AIM: To investigate the association of visual impairment from cataract with human development index(HDI) by years lived with disability(YLDs).METHODS: Published data on national age-standardized YLD rates caused by cataract and national HDIs in 2019 were obtained. Age-standardized YLD rates from 1990 to 2019 were analyzed to explore cataract burden among patients with different income levels. Age-standardized YLD rates in different HDI groups were compared by different degrees of visual impairment. Association between national age-standardized YLD rates and HDI in 2019 was analyzed.RESULTS: The age-standardized YLD rates of populations with visual impairment or blindness due to cataract declined from 1990 to 2019, especially among those with lower middle income. Multiple comparison tests revealed that countries with low HDI had significantly higher agestandardized YLD rates of blindness due to cataract than those with high and very high HDI(P<0.001). The agestandardized YLD rates of populations with blindness(β=-0.588, P<0.001), severe vision loss(β=-0.378, P<0.001), and moderate vision loss(β=-0.389, P<0.001) inversely correlated with HDI.CONCLUSION: Age-standardized YLD rates caused by cataract have declined since 1990. The burden of visual impairment due to cataract inversely correlate with national socioeconomic development and is more concentrated in countries with low HDI than those with high HDI, especially among the blind. These findings highlight the need to provide additional cataract services and cataract surgery coverage to developing countries to decrease the burden of avoidable blindness caused by cataract.