The global socioeconomics of vision impairment and cataract surgery

Abstract

The overwhelming majority of the world’s vision impaired reside in low-income settings. Cataract is the leading cause of blindness and the second-leading cause of moderate to severe vision impairment (MSVI). Proxy measures of cataract disease burden and access to cataract surgery services include cataract surgery rate (CSR) and cataract surgery coverage (CSC) rates.

The present research aims to evaluate and model associations between the scale of vision loss and burden of cataract disease with socioeconomic indices, drawing comparisons with other countries globally to identify key country policies, practices and initiatives that have resulted in significant improvements to service delivery.

A meta-analysis was conducted using CSR data between 2005 and 2014 from published literature and unpublished literature. A systematic review of Rapid Assessment of Avoidable Blindness (RAAB) studies from 1995 to 2015 extracted information on the prevalence and causes of blindness, rate of cataract blindness, cataract surgery coverage (CSC), and visual acuity outcomes of cataract surgery (CSO). HDI and GDP data were collected from the United Nations Development Program (UNDP) and World Bank repositories respectively. Estimates of age-standardised prevalence data of vision impairment and blindness were collected from the 2010 Global Burden of Disease Study (GBD).

CSR was found to be closely associated with GDP and GNI using data throughout the study period. HDI levels accounted for the majority of global variance in the prevalence of moderate-severe VI and blindness. Of the three HDI components, education was identified as the most influential factor, accounting for two-thirds of the global variance in MSVI and blindness prevalence. Lower total health expenditure per capita, and as a proportion of total GDP, were associated with a higher prevalence of moderate-severe VI and blindness.

A strong association exists between socioeconomic factors as indicated by GDP, GNI and HDI and the quality and quantity of cataract surgery. This suggests there are strong relationships between resource availability and healthcare delivery. Low-cost and innovative services as well as strategic investment in capacity development is important to address cataract surgery needs in low-resource settings.