White matter hyperintensities, retinal vascular calibre and changes in age-related hearing loss

Cerebral small vessel disease may contribute to age-related hearing loss pathogenesis by reducing blood flow to the cochlea and/or areas of the brain important for hearing. Cerebral white matter hyperintensities (WMHs) and retinal vascular calibre are both considered to be non-invasive markers of cerebral small vessel health. This study investigated the relationship between age-related hearing loss, retinal vascular calibre and WMHs in older adults using data from the ASPirin in Reducing Events in the Elderly (ASPREE) trial, including participants who underwent hearing assessment, retinal photography and brain magnetic resonance imaging. Participants were free of evident cardiovascular disease at recruitment between 2010 and 2014. Retinal vascular calibre was measured using central retinal arteriolar and venular equivalents. Total brain WMH volumes were calculated using an automated lesion prediction algorithm and further segmented as deep WMH and periventricular WMH. Hearing acuity was assessed using pure tone audiometry and speech perception in background noise. A total of 308 participants (aged 70+) were included. In both cross-sectional and longitudinal analyses no associations were found between baseline central retinal arteriolar equivalent, central retinal venular equivalent, total WMH, deep WMH or periventricular WMH in relation to changes in audiometric 0.5, 4 and 8 kHz thresholds or speech perception after adjusting for confounding factors. This study identified no relationship between retinal vascular calibre, WMH volumes and hearing function in healthy older adults. This suggests that microvascular changes in the eye and brain may occur independently of changes in auditory function in older individuals.