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The following is a summary of “Visual Impairment and Cognitive Function in Aging Adults: Sex and Age Differences in Mediating Effect of Social Isolation and Depression,” published in the March 2025 issue of American Journal of Ophthalmology by Zheng et al. 

Visual impairment (VI) was common in older adults (OAs) and linked to cognitive decline, though its impact on cognitive functioning during aging remained unclear.  

Researchers conducted a retrospective study to assess the direct effect of visual acuity (VA) on cognitive function and its indirect effect through social isolation and depressive symptoms, analyzed by sex and age.  

They analyzed data from 1,17,231 individuals aged 40-70 in the UK Biobank baseline and ocular assessment, with 81% being white, 54% female, and 45.6% aged 60-70. The mean age was 56.8 years (SD 8.1). Path analyses with multiple equations examined the direct and indirect effects of VA, with stratified analyses by gender and age. The LogMAR VA was the exposure, while social isolation and depressive symptoms were mediators. Cognitive functions, including visual memory, verbal-numerical reasoning, processing speed, and prospective memory, were assessed as outcomes.  

The results showed that VA had a direct impact on cognitive function (β=-0.979, P <0.01 for reasoning; OR=0.67, P <0.01 for prospective memory). The VA also affected cognition indirectly through social isolation and depressive symptoms (all P <0.01). The direct effect of VA on cognition remained consistent across sex and age groups (all P <0.05). However, the mediating effects varied, with social isolation having a stronger impact in OAs and men, while depressive symptoms had a greater effect in women and middle-aged individuals. The strongest mediating effect via social isolation was observed in older males.  

Investigators concluded that addressing vision impairment, social isolation, and depression could preserve cognition, reduce dementia risk, and improve well-being in aging adults by promoting targeted social engagement and mental health awareness. 

Source: ajo.com/article/S0002-9394(25)00108-4/abstract