Vision loss and depression are common conditions with major health implications. However, the mechanism of that association remains to be clarified.
A collaboration between Chinese and Australian researchers found that visual health may be associated with depressive symptoms and altered brain neurobiology,1 according to Xiayin Zhang, PhD, from the Guangdong Eye Institute, Department of Ophthalmology, and the Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
She explained that vision loss and depression are common conditions with major health implications. However, the mechanism of that association remains to be clarified.
She and fellow researchers set out to investigate the connection in the UK Biobank Study cohort. In this study, conducted from March to June 2006 to July 2010 that included 114,583 volunteers (54.5% women; mean participant age, 56.8 years; range, 39-72 years), the investigators studied the association between depression and brain micro- and macrostructure in subgroups divided by visual acuity (VA).
The habitual distance VA was measured using the logarithm of the minimum angle of resolution (logMAR) characters. Depression was identified based on the Patient Health Questionnaire (PHQ) or through an interview-based psychiatric diagnosis. Subgroup participants underwent multimodal magnetic resonance imaging (MRI) of the brain and PHQ evaluation during the imaging visit after 2014.
The main outcomes and measures were depression, depressive symptoms, and imaging-derived phenotypes from T1-weighted and diffusion MRI.
The results indicated that a 1-line worse VA (0.1 logMAR increase) was associated with a 5% higher odds of depression (odds ratio, 1.05; 95% confidence interval [CI], 1.04-1.07) after adjustment for age; sex race; ethnicity; Townsend index; educational qualifications; smoking; alcohol consumption; obesity; physical activity; history of hypertension, diabetes, and hyperlipidemia; and family history of depression.
The investigators reported that of the 7,844 participants who underwent MRI, “a linear association was seen between the PHQ score and the left volume of gray matter in the supracalcarine cortex (coefficient, 7.61; 95% CI, 3.90-11.31) and the 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. In addition, their association could be moderated by VA, whereby an increased PHQ score was associated with higher ISOVF levels only among those with poorer VA (P = 0.02 for interaction).”
The results suggested an association between visual health and depression and that the diffusion characteristic of ISOVF in the fornix (cres) and/or stria terminalis is associated with depressive symptoms in participants with poorer VA.
Zhang advised that health care providers consider these outcomes when performing routine mental health screening.