Eye-brain structural alterations and associated neurotransmitter profiles in high myopia: Evidence from cross-modal...

Evidence suggests that high myopia is associated with concomitant structural and functional alterations in both the eye and the brain. However, the interactions between the brain and the eye and their underlying regulatory mechanisms remain uncertain. This study aims to investigate the changes in eye morphology and brain structure in patients with high myopia, as well as the potential alterations in neurotransmitter profiles, utilizing a combined approach to study eye-brain interactions in high myopia patients. Our analysis revealed altered gray matter volume (GMV) in eight brain regions of patients with high myopia (all P < 0.05, Gaussian random field corrected). These regions are the right inferior frontal gyrus (orbital and triangular parts), left amygdala, left temporal pole, right supplementary motor area, left precuneus, right lingual gyrus, right occipital lobe, and right hippocampus. Notably, both axial length and eye volume showed negative correlations with GMV in specific subregions of the inferior frontal gyrus (triangular part: ρ= -0.520, -0.435; orbital part: ρ = -0.598, -0.439; all P < 0.05). Furthermore, the identified GMV alterations were significantly associated with the density of specific neurotransmitter receptors, including 5-HT1b, 5-HT2a, D1, and mGluR5 (P < 0.005, Bonferroni correction). These findings demonstrate a pattern of eye-brain structural covariation in high myopia, which may be modulated by neurotransmitter systems.