Altered Resting State Functional Connectivity Patterns of Hippocampal Subregions in PACG Patients with Cognitive Dysfunction

Background/Objectives: Patients with glaucoma often exhibit cognitive dysfunction. Identifying imaging markers of glaucoma-related cognitive dysfunction can guide early clinical interventions. Method: This study included 44 primary angle-closure glaucoma patients (PACG) with cognitive dysfunction, and 46 healthy controls (HCs). Participants underwent 3D high-resolution T1 structural imaging and BOLD fMRI scanning. Seven hippocampus subregions were selected as seed regions to explore changes in functional connectivity (FC) between the bilateral hippocampal subregions and the whole brain in PACG patients with cognitive dysfunction. Results: Compared with the HCs group, the PACG group showed decreased FC between multiple hippocampus subregions and the cerebellum, precentral gyrus, postcentral gyrus, supplementary motor area, supramarginal gyrus, inferior frontal gyrus, opercular part, lenticular nucleus, pallidum, rolandic operculum, and inferior parietal, supramarginal, and angular gyri. However, increased FC was found between the bilateral hippocampal subregions and the calcarine fissure and the surrounding cortex, lingual gyrus, anterior cingulate, and paracingulate gyri. We also found that FC between the hippocampal subregion and some brain regions was associated with visual acuity, average cup-to-disc ratio, and retinal nerve fibre layer thickness. Conclusion: Extensive FC abnormalities between the hippocampal subregion and cerebellum, sensorimotor network, default mode network, visual network, and other brain areas were found in PACG patients with cognitive dysfunction, providing new insights into the neuropathological mechanisms and potential neuroimaging biomarkers for early diagnosis and intervention.