Retinal Vascular Density on Optical Coherence Tomography Angiography and Age-related Central and Peripheral Hearing Loss in a Southern Italian Older Population

Background: Age-related hearing loss (ARHL) and retinal vessel changes have both been associated to neurodegeneration/dementia, suggesting a possible link between these 2 conditions in older age. We aimed to determine whether superficial and deep vascular density (SVD and DVD) of the capillary plexi of macular vasculature can be associated with peripheral ARHL and age-related central auditory central processing (CAPD). Method: We analyzed data on 886 older participants (65 years+, age range: 65-92 years) in the cross-sectional population-based Salus in Apulia Study. Optical coherence tomography angiography was used to measure SVD and DVD of the capillary plexi of the macula at the 3-mm circle area centered on the fovea (whole retina), the parafoveal quadrant, and foveal quadrant. Disabling peripheral ARHL was defined as >40 dB hearing level of pure tone average on the frequencies from 0.5, 1, 2, and 4 KHz in the better ear, and age-related CAPD as <50% at the Synthetic Sentence Identification with Ipsilateral Competitive Message test in at least one ear. Results: DVD at the whole retina and at the parafoveal quadrant were inversely associated only with age-related CAPD (odds ratio [OR]: 0.93, 95% confidence interval [CI]: 0.88-0.96 and OR: 0.94, 95 CI: 0.90-0.99, respectively). No further associations with peripheral ARHL were evident. Conclusions: Retinal vasculature is associated with central auditory processing pathology, possibly playing an important role in early detection and intervention. The association of retinal vascular density with age-related CAPD may bring us a further step forward in understanding the biological mechanisms underlying the links between neurodegeneration/dementia and ARHL.