Key points Is visual health across the visual acuity spectrum associated with depressive symptoms and corresponding changes in brain imaging signatures among middle-aged and older adults? Findings In this cohort study of 114,583 UK Biobank Study participants, poorer visual acuity was associated with depressive symptoms as measured by the Patient Health Questionnaire score across the spectrum. Furthermore, poorer visual acuity exacerbated linear associations between Patient Health Questionnaire score and extracellular water diffusion in the fornix (cres) and/or stria terminalis. Meaning These findings suggest that visual health is associated with depressive symptoms and altered brain neurobiology and that healthcare professionals should consider these results when performing routine mental health screenings. |
Good visual functioning is essential for satisfaction and value among older adults. With advanced aging, vision-related problems have important public health implications and contribute to difficulties in activities of daily living, morbidity, and mortality in middle-aged and older adults.
It is well known that visual impairment contributes to the burden of depression. The mechanisms underlying their relationship are complex, but 2 main pathways can be identified.
1. First, poor eye conditions and depression share common risk factors, including poverty.
2. Secondly, visual impairment can cause depression due to difficulties in reading, moving and driving.
A previous meta-analysis indicated that 1 in 4 elderly patients with visual impairment reported depression. However, the association between depression and the full spectrum of visual acuity remains unclear.
Depression is another major burden on society that is projected to rank as the leading cause of disease burden worldwide by 2030. Depression in older adults is subtle and often goes unrecognized and unrecognized. adequately treated, while current drug treatment is generally effective against severe depression. Therefore, managing poorer visual acuity may help reduce the prevalence of depression.
It has been shown that depression also causes alterations in brain structures and functional connections.
Conventional magnetic resonance imaging (MRI) has been used to investigate pathological changes, and diffusion MRI (dMRI) allows mapping of cortical connections. 19Meta-analyses using MRI and dMRI have shown that depression is associated with volumetric reductions in the hippocampus, lower fractional anisotropy, and increased radial diffusivity.
Because poorer visual acuity and depression can coexist in people, more research is needed to understand the brain changes and the neural mechanisms linked between them.
The present study aims to investigate the association between visual health (across the spectrum of visual acuity) and depressive symptoms in a large sample of middle-aged and older adults from the UK Biobank cohort. The combination of a large cohort of participants and multimodal imaging data is a unique feature of the UK Biobank Study that provides information on image-derived phenotypes (IDPs) of brain macrostructure and microstructure and, in addition, estimates neurite density ( i.e., intracellular volume fraction), extracellular water diffusion (i.e., isotropic volume fraction [ISOVF]), and tract and/or fan complexity (i.e., orientation dispersion).
Our objective was to characterize alterations in brain structures due to depressive symptoms measured by the Patient Health Questionnaire (PHQ) tool. We hypothesized that poorer visual acuity would be associated with depression and could alter depression-related brain structures.
Importance
Vision loss and depression are common conditions with important health implications. However, the mechanisms of the association of visual health (across the spectrum of visual acuity) with depression remain unclear.
Aim
To characterize the association between visual health and depression and investigate the association between depression and brain microstructure and macrostructure in subgroups divided by visual acuity.
Design, environment and participants
In the UK Biobank Study cohort, 114,583 volunteers were included at baseline from March to June 2006 to July 2010. Usual distance visual acuity was examined using logarithm of the minimum angle of resolution (LogMAR) traits. Depression was identified based on the Patient Health Questionnaire (PHQ) or through an interview-based psychiatric diagnosis. Subgroup participants completed a multimodal brain MRI and PHQ assessment during the imaging visit after 2014. Data were analyzed from May 5 to August 9, 2022.
Main results and measures
Depression, depressive symptoms, and phenotypes derived from T1-weighted and diffusion magnetic resonance imaging.
Results
Of the 114,583 participants in the UK Biobank Study, 62,401 (54.5%) were women and the mean (SD) age was 56.8 (8.1) years (range, 39-72 years). A 1-line worse visual acuity (LogMAR increase of 0.1) was associated with a 5% increased odds of depression (odds ratio, 1.05 [95% CI, 1.04-1.07]) after adjustment for age, sex, race and ethnicity, Townsend index, education, smoking, alcohol consumption, obesity, physical activity, history of hypertension, diabetes, hyperlipidemia, and family history of depression.
Of the 7844 participants eligible for MRI analysis, there were linear associations between PHQ score and left gray matter volume in the supracalcarine cortex (ratio, 7.61 [95% CI, 3.90-11.31 ]) and mean isotropic volume fraction (ISOVF) in the right fornix (cres) and/or stria terminalis (coefficient, 0.003 [95% CI, 0.001-0.004]) after correction for multiple comparison. Furthermore, their association could be moderated by visual acuity, such that increasing PHQ score was associated with higher ISOVF levels only among those with worse visual acuity (p = 0.02 for interaction).
Conclusions and relevance This study suggests an association between visual health and depression and that the diffusion feature of ISOVF in the fornix (cres) and/or stria terminalis is associated with depressive symptoms in participants with lower visual acuity. |
