Association Between Area Temperature and Severe Vision Impairment in a Nationally Representative Sample of Older Americans.

Abstract

Purpose: Several small studies have associated exposure to elevated average temperature with specific vision problems. However, no large-scale studies have examined the relationship between vision impairment and average area temperature in the general population. We conducted a cross-sectional analysis of a large nationally representative sample of older adults to further explore this relationship.

Methods: Secondary analysis of the American Community Survey (ACS). The survey was conducted through mail, telephone and in-person interviews. Data from six consecutive years of the cross-sectional survey were analysed (2012-2017). The subsample analysed included community-dwelling and institutionalized older adults aged 65 and older in the coterminous US who lived in the same state in which they were born (n = 1,707,333). The question on severe vision impairment was "Is this person blind or does he/she have serious difficulty seeing even when wearing glasses?". Average annual temperature data from the National Oceanic and Atmospheric Administration was combined into a 100-year average and mapped to corresponding US Census Bureau's public use microdata areas from the ACS.

Results: Higher average temperature is consistently associated with increased odds of severe vision impairment across all cohorts (i.e. age, sex, race, income, and educational attainment cohorts) with the exception of Hispanic older adults. Compared to those who lived in counties with average temperature of < 50 °F (< 10 °C) , the odds of severe vision impairment were 44% higher in counties with average temperature of 60 °F (15.5 °C) or above (OR 1.44; 95% CI 1.42-1.46).

Conclusion: If the association is found to be causal, the predicted rise in global temperatures could impact the number of older Americans affected by severe vision impairment and the associated health and economic burden.