Vision Impairment and Receipt of Eye Care Among Older Adults in Low- and Middle-Income Countries

Abstract

Importance: Vision impairment (VI), including blindness, affects hundreds of millions globally, and 90% of those with VI live in low- and middle-income countries. Cross-national comparisons are important to elucidate the unique and shared factors associated with VI and receipt of eye care in different countries and to target those most in need.

Objective: To identify the characteristics associated with VI and receipt of eye care in a sample of low- and middle-income countries.

Design, setting, and participants: In this study of cross-sectional survey data from wave 1 of the World Health Organization Study on Global Aging and Adult Health, data on sociodemographic characteristics and health were collected from nationally representative samples in China, Ghana, India, Mexico, Russia, and South Africa from 2007 to 2010. Probability sampling with multistage, stratified, random-cluster samples was used to identify households and participants. The survey was completed by 34 159 adults 50 years and older. Data were analyzed from December 2017 to February 2018.

Main outcomes and measures: We analyzed associations of individual-level and household-level covariates with 3 primary outcomes: distance VI (visual acuity worse than 6/18 in the better-seeing eye), near VI (visual acuity worse than 6/18 in the better-seeing eye), and receipt of an eye examination within the previous 2 years.

Results: The study sample in China consisted of 13 350 participants (50.2% female; mean [SD] age, 62.6 [9.0] years); in Ghana, 4725 participants (50.4% female; mean [SD] age, 64.2 [10.8] years); in India, 7150 participants (48.9% female; mean [SD] age, 61.5 [9.0] years); in Mexico, 2103 participants (52.3% female; mean [SD] age, 69.2 [9.2] years); in Russia, 3763 participants (61.1% female; mean [SD] age, 63.9 [10.4] years); and in South Africa, 3838 participants (55.9% female; mean [SD] age 61.6 [9.5]) (all demographic characteristics weighted to reflect respective populations). The weighted proportion of the study sample with distance VI ranged from 9.9% (95% CI, 9.3-10.5) in China to 25.4% (95% CI, 22.0-29.2) in Russia; near VI, from 28.5% (95% CI, 26.9-30.1) in Ghana to 43.1% (95% CI, 41.1-45.1) in India; and receipt of a recent eye examination, from 15.0% (95% CI, 13.8-16.2) in Ghana to 53.1% (95% CI, 49.3-56.8) in Russia. Educational attainment, medical comorbidities, and memory were significantly associated with all outcomes across most low- and middle-income countries. Female sex, low household wealth, food insecurity, no health insurance, rurality, disability, being unmarried, and low social participation were significantly associated with adverse vision-related outcomes, though less consistently.

Conclusions and relevance: There are both common and unique characteristics associated with VI and receipt of eye care across low- and middle-income countries. Our findings suggest that recognizing these factors is important to identify those most at risk and allocate resources optimally. Additional local epidemiological studies are needed.

Figure.. Heat Maps of Unadjusted Associations of Demographic, Socioeconomic, and Health-Related Variables With Distance Vision Impairment (VI), Near VI, and Receipt of a Recent Eye Examination

The legend applies to all 3 heat maps and shows the effect size (based on odds ratios) depicted by various colors. Variables with a strong positive and negative association with the outcome are illustrated by progressively darker shades of hot and cold colors, respectively. Unadjusted associations with distance VI, near VI, and receipt of a recent eye examination are depicted. Odds ratios were calculated using logistic models, and reference groups are noted last in the variable descriptions. Mild VI indicates visual acuity between worse than 6/12 and 6/18 or better; moderate VI, between worse than 6/18 and 6/60 or better; severe VI, worse than 6/60 and 6/120 or better; and blindness, worse than 6/120.