Differential structural and functional impairments in cytoarchitectonic areas of the visual pathway in glaucoma

Motivation: Glaucoma causes progressive degeneration throughout the visual pathway. While structural atrophy has been well-documented, a comprehensive analysis that includes both structural and functional impairments remains essential. Goal(s): To evaluate structural atrophy and functional changes in cytoarchitectonic areas along the visual stream, including the lateral geniculate nucleus (LGN), visual cortex (hOc1-4), and fusiform gyrus (FG1-4), in glaucoma patients. Approach: Structural and functional MRI was employed to assess brain volume and functional responses in healthy controls, early glaucoma, and advanced glaucoma groups. Results: The study identified volumetric shrinkage exclusively in the LGN, with functional impairments observed across the LGN, hOc1-4, and FG1 regions. Impact: Our findings suggest that functional impairments are more pronounced than structural changes in the visual pathway, including the LGN, visual cortex, and fusiform gyrus, in glaucoma. This highlights the importance of studying functional impairments in higher-level visual areas in glaucoma.