Cortical plasticity in central vision loss: Cortical thickness and neurite structure

• Published in: Human brain mapping Vol. 44; no. 10; pp. 4120 - 4135
• Main Authors: Defenderfer, Matthew K., Demirayak, Pinar, Fleming, Leland L., DeCarlo, Dawn K., Stewart, Paul, Visscher, Kristina M.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.07.2023
• Subjects: Age; central vision loss; cortical thickness; Density; Dispersion; Eye diseases; Gender; Humans; Lesions; Macular degeneration; Macular Degeneration - pathology; Neural plasticity; Neurites - pathology; NODDI; Orientation; Peripheral vision; Retina; Retina - pathology; Somatosensory cortex; Thickness; Visual acuity; Visual Cortex - diagnostic imaging; Visual Cortex - pathology; Visual field; Visual Fields; Visual Perception; NODDI; central vision loss; cortical thickness; macular degeneration
• ISSN: 1065-9471; 1097-0193
• DOI: 10.1002/hbm.26334

Late‐stage macular degeneration (MD) often causes retinal lesions depriving an individual of central vision, forcing them to learn to use peripheral vision for daily tasks. To compensate, many patients develop a preferred retinal locus (PRL), an area of peripheral vision used more often than equivalent regions of spared vision. Thus, associated portions of cortex experience increased use, while portions of cortex associated with the lesion are deprived of sensory input. Prior research has not well examined the degree to which structural plasticity depends on the amount of use across the visual field. Cortical thickness, neurite density, and orientation dispersion were measured at portions of cortex associated with the PRL, the retinal lesion, and a control region in participants with MD as well as age‐matched, gender‐matched, and education‐matched controls. MD participants had significantly thinner cortex in both the cortical representation of the PRL (cPRL) and the control region, compared with controls, but no significant differences in thickness, neurite density, or orientation dispersion were found between the cPRL and the control region as functions of disease or onset. This decrease in thickness is driven by a subset of early‐onset participants whose patterns of thickness, neurite density, and neurite orientation dispersion are distinct from matched control participants. These results suggest that people who develop MD earlier in adulthood may undergo more structural plasticity than those who develop it late in life. Retinal sensitivity is measured in both eyes of patients with central vision loss due to macular degeneration. Instead of using the fovea for daily tasks as most people with healthy vision do, many patients use a “Preferred retinal locus” instead. We ask how the anatomy of the cortical projection of that preferred retinal locus changes with experience.