Is the Retina a Mirror of the Aging Brain? Aging of Neural Retina Layers and Primary Visual Cortex Across the Lifespan

Abstract

How aging concomitantly modulates the structural integrity of the brain and retina in healthy individuals remains an outstanding question. Given the strong bottom-up retinocortical connectivity, it is important to study how these structures co-evolve during healthy aging in order to unravel mechanisms that may affect the physiological integrity of both structures. For the 56 participants in the study, primary visual cortex (BA17), as well as frontal, parietal and temporal regions thicknesses were measured in T1-weighted magnetic resonance imaging (MRI), and retinal macular thickness (10 neuroretinal layers) was measured by optical coherence tomography (OCT) imaging. We investigated the statistical association of these measures and their age dependence. We found an age-related decay of primary visual cortical thickness that was significantly correlated with a decrease in global and multiple layer retinal thicknesses. The atrophy of both structures might jointly account for the decline of various visual capacities that accompany the aging process. Furthermore, associations with other cortical regions suggest that retinal status may index cortical integrity in general.

Normative Database for All Retinal Layer Thicknesses Using SD-OCT Posterior Pole Algorithm and the Effects of Age, Gender and Axial Lenght

“…The thickness of inner retinal layers correlated negatively with age, and this finding is also consistent with previous studies [ 17 , 21 , 31 , 37 ] that documented GCL, IPL and INL thinning with age. We were unable to document a significant correlation between age and RNFL, OPL and RPE thicknesses as reported by Jorge et al [ 37 ]. However, we found that RNFL underwent significantly decreased thickness with age in several inferonasal and peripapillary cells.…”

“…We do not know if the reason for OPL thickening could be the thickening of Henle’s fiber layer with age [ 41 ]. We did not find any significant correlation between RPE thickness and age as previous research works report [ 31 , 36 , 37 ]. However, we observed a highly significant negative correlation between age and RPE thickness in some central cells which, to our knowledge, has not been reported before.…”

“…The age-related decline in GCL thickness has been widely reported in both histological [ 32 , 33 ] and clinical [ 34 , 35 , 36 , 37 ] studies. The thickness of inner retinal layers correlated negatively with age, and this finding is also consistent with previous studies [ 17 , 21 , 31 , 37 ] that documented GCL, IPL and INL thinning with age. We were unable to document a significant correlation between age and RNFL, OPL and RPE thicknesses as reported by Jorge et al [ 37 ].…”

Linked deterioration of early visual perception, function and structure in healthy human aging

“…Regarding the retina, our OCT measures of retinal structure are also consistent with previous reports of gradual loss of retinal ganglion cells and their axons during healthy aging 1,2,3,22 . We propose that this retinal ganglion cell loss is likely to cause the decreases in visual field map surface areas, and (indirectly) the increases in pRF size, that we observe.…”

The Retinal Inner Plexiform Synaptic Layer Mirrors Grey Matter Thickness of Primary Visual Cortex with Increased Amyloid β Load in Early Alzheimer’s Disease

“…In turn, no association was found in the MCI or AD groups [ 96 ]. A recent study from our group also found retinocortical associations in healthy aging [ 98 ].…”