Summary: A comprehensive meta-analysis shows that people with vision impairment or blindness face a significantly higher risk of death from any cause compared with people who have normal or only mild vision loss. The pooled results indicate a 29% higher mortality risk for those with mild visual impairment, rising to an 89% higher risk for individuals with severe vision impairment.
Source: University of Michigan
The world’s population is aging, and age-related vision problems are increasing. Projections indicate that the number of people living with vision impairment and blindness will more than double over the next three decades.
A meta-analysis published in The Lancet Global Health, which pooled data from 48,000 participants across 17 studies, found that worse vision was associated with a higher risk of all-cause mortality compared with normal or only mildly reduced vision.
Across the combined studies, participants with mild vision impairment faced a 29% greater risk of death than those with normal vision. The mortality risk climbed substantially with greater vision loss, reaching an 89% increase among people with severe vision impairment.
Crucially, up to four in five cases of vision impairment are preventable or treatable. Globally, the most common causes of avoidable vision loss and blindness are cataracts and uncorrected refractive error—conditions that can often be corrected with surgery or eyeglasses.
Study lead author Joshua Ehrlich, M.D., M.P.H., aimed to clarify the relationship between visual disability and all-cause mortality, bringing together evidence from multiple population studies to assess the strength and consistency of that association.
This analysis builds on related work by Ehrlich and colleagues in The Lancet Global Health Commission on Global Eye Health, which examined how vision loss in later life affects quality of life, independence, and risks for conditions such as dementia and depression.
“Addressing vision problems early is essential,” says Ehrlich. “Vision loss affects more than sight—it changes how people experience daily life and can influence overall health and longevity. Preventing and treating avoidable vision loss worldwide could improve both wellbeing and survival.”
Funding: This research received support from Wellcome Trust, the Commonwealth Scholarship Commission, the National Institutes of Health, Research to Prevent Blindness, the Queen Elizabeth Diamond Jubilee Trust, Moorfields Eye Charity, the National Institute for Health Research, Moorfields Biomedical Research Centre, Sightsavers, the Fred Hollows Foundation, the Seva Foundation, the British Council for the Prevention of Blindness, and Christian Blind Mission.
About this visual neuroscience research news
Source: University of Michigan
Contact: Jordyn Imhoff – University of Michigan
Image: The image is in the public domain
Original Research: Closed access.
“Association between vision impairment and mortality: a systematic review and meta-analysis” by Ehrlich et al., Lancet Global Health
Abstract
Association between vision impairment and mortality: a systematic review and meta-analysis
Background
As populations age, the global burden of vision impairment is growing. This study aimed to systematically identify and synthesize evidence on the relationship between vision impairment and risk of death from any cause, focusing on adults aged 40 years or older.
Methods
Researchers searched major medical databases up to Feb 1, 2020, for studies in English that examined the association between vision impairment and all-cause mortality. Eligible studies included prospective and retrospective cohort studies, and in some cases randomized controlled trials, provided that visual impairment and mortality associations were independent of trial interventions. Studies were required to include participants aged 40 or older with at least one year of follow-up and to report age-adjusted mortality estimates. Two reviewers independently screened studies, extracted data, and assessed risk of bias. The team graded the certainty of the evidence and used random-effects meta-analysis to calculate pooled, maximally adjusted hazard ratios comparing specified vision thresholds (for example, visual acuity <6/12 versus ≥6/12).
Findings
The search identified 3,845 articles; 28 studies representing 30 cohorts (446,088 participants) were included in the systematic review, and 17 studies (18 cohorts; 47,998 participants) contributed to the meta-analysis. Measurement methods for vision varied across studies. Pooled hazard ratios indicated a 1.29-fold increase in all-cause mortality for visual acuity <6/12 versus ≥6/12, and a 1.43-fold increase for <6/18 versus ≥6/18. For more severe impairment (<6/60 versus ≥6/18), the hazard ratio was 1.89. Heterogeneity between studies was generally low. Some studies were judged low risk of bias across domains, while others showed higher risk in one or more areas. Effect sizes were larger in studies using best-corrected visual acuity compared with presenting visual acuity. Overall, the evidence was rated as of moderate certainty.
Interpretation
People with vision impairment have a higher hazard of all-cause mortality compared with those who have normal vision or only mild impairment, and the risk increases with the severity of vision loss. These findings underscore the public health importance of preventing, correcting, and rehabilitating avoidable vision impairment to support healthy aging and contribute to global development goals.
Funding
Wellcome Trust, Commonwealth Scholarship Commission, National Institutes of Health, Research to Prevent Blindness, the Queen Elizabeth Diamond Jubilee Trust, Moorfields Eye Charity, National Institute for Health Research, Moorfields Biomedical Research Centre, Sightsavers, the Fred Hollows Foundation, the Seva Foundation, the British Council for the Prevention of Blindness, and Christian Blind Mission.