Number of People Blind or Visually Impaired by Cataract Worldwide and in World Regions, 1990 to 2010

Abstract

PURPOSE.To estimate prevalence and number of people visually impaired or blind due to cataract. METHODS.Based on the Global Burden of Diseases Study 2010 and ongoing literature research, we examined how many people were affected by moderate to severe vision impairment (MSVI; presenting visual acuity <6/18, ‡3/60) and blindness (presenting visual acuity <3/60) due to cataract. RESULTS.In 2010, of overall 32.4 million blind and 191 million vision impaired, 10.8 million people were blind and 35.1 million were visually impaired due to cataract. Cataract caused worldwide 33.4% of all blindness in 2010, and 18.4% of all MSVI. These figures were lower in the high-income regions (<15%) and higher (>40%) in South and Southeast Asia and Oceania. From 1990 to 2010, the number of blind or visually impaired due to cataract decreased by 11.4% and by 20.2%, respectively; the age-standardized global prevalence of cataract-related blindness and MSVI reduced by 46% and 50%, respectively, and the worldwide crude prevalence of cataract-related blindness and MSVI reduced by 32% and 39%, respectively. The percentage of global blindness and MSVI caused by cataract decreased from 38.6% to 33.4%, and from 25.6% to 18.4%, respectively. This decrease took place in almost all world regions, except East Sub-Saharan Africa.CONCLUSIONS. In 2010, one in three blind people was blind due to cataract, and one of six visually impaired people was visually impaired due to cataract. Despite major improvements in terms of reduction of prevalence, cataract remains a major public health problem.Keywords: cataract, epidemiology, blindness, visual impairment A lthough cataract is relatively easily, safely, and costefficiently treatable, and in spite of the increasing rates of cataract surgery, 1 cataract is still the leading cause of blindness and visual impairment worldwide, especially in developing countries. 2,3 Population-based studies and previous meta-analyses performed in different regions worldwide have reported that cataract is responsible for 47.8% to 51% of all global blindness. 2,4-9 However, these studies did not report data on the change during the past 2 decades in terms of prevalence and number of people blind or visually impaired due to cataract.The purpose of the current study was to determine, in a meta-analysis of all available population-based studies performed worldwide within the past 2 decades, prevalence and number of people affected by blindness and visual impairment due to cataract, to assess changes during the period from 1990 to 2010, and to examine regional differences in the prevalence of cataract-related blindness and visual impairment.

Variations and Trends in Health Burden of Visual Impairment Due to Cataract: A Global Analysis

“…18 Among the 21 Super Regions, the prevalence of cataract blindness was highest in Oceania, followed by South and Southeast Asia, and the lowest in high-income countries. 1 Consistent with previous studies, the present study observed an unevenly distributed health burden of cataract. The levels of health burden in Southeast Asia, the Eastern Mediterranean, and Africa were higher than the global level; addressing this should be a priority in future programs.…”

“…1 Globally, 10.8 million were blind and 35.1 million people were visually impaired from cataract in 2010.…”

“…It was estimated that the prevalence of cataract vision loss was decreasing during the period between 1990 and 2010 in all countries, with the exception of eastern Sub-Saharan Africa. 1,11 From 1990 to 2010, the number of people with cataract blindness was reduced by 11.4%, and the percentage of blindness due to cataract decreased from 38.6% to 33.4%. This may be associated with global action such as VISION 2020, which set cataract as a priority, and national programs such as the China Million Cataract Surgeries Program.…”

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Age-related cataracts are a worldwide cause of blindness in 10.8 million of people and 35.1 million were visually impaired in 2010, it means that cataract caused 33.4% of blindness and 18.5% of moderate to severe vision impairment [1]. Cataract prevalence increase as people age, by age 75, half of population have a cataract; by age 80, 70% of whites, 53% of Africans and 61% of Hispanics [1,2].

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“…Cataract prevalence increase as people age, by age 75, half of population have a cataract; by age 80, 70% of whites, 53% of Africans and 61% of Hispanics [1,2]. Cataract surgery is a successful procedure in the majority of cases (about 95%) [2].…”