Hippocampal subregions functional connectivity alterations in primary angle-closure glaucoma patients with cognitive...

Cognitive dysfunction has been reported in patients with glaucoma, but the underlying neural mechanisms remain unclear. This study aimed to explore functional connectivity (FC) alterations in hippocampal subregions in primary angle-closure glaucoma (PACG) patients with cognitive impairment.

This study included forty-four PACG patients with cognitive dysfunction, and forty-six healthy controls (HCs). Participants underwent 3D high-resolution T1 structural imaging and BOLD fMRI scanning. Seven hippocampal subregions were selected as seed regions to explore changes in FC between the bilateral hippocampal subregions (Cornu Ammonis 1, Cornu Ammonis 2, Cornu Ammonis 3, Dentate gyrus, Entorhinal cortex, HATA, Subiculu) and the whole brain in PACG patients with cognitive dysfunction.

Compared with the HCs group, the PACG group showed decreased FC between multiple hippocampal subregions and the cerebellum, precentral gyrus, postcentral gyrus, supplementary motor area, supramarginal gyrus, inferior frontal gyrus, opercular part, lenticular nucleus, pallidum, rolandic operculum, inferior parietal, supramarginal, and angular gyri. However, increased FC was found between the bilateral hippocampal subregions and the calcarine fissure and surrounding cortex, lingual gyrus, anterior cingulate, and paracingulate gyri. We also found that FC between hippocampal subregions and some brain regions were associated with visual acuity, average cup-to-disc ratio, and retinal nerve fibre layer thickness.

These findings reveal widespread hippocampal FC alterations involving the cerebellum, sensorimotor, default mode, and visual network (VN) in PACG patients with cognitive dysfunction, contributing to a better understanding of the underlying neural mechanisms.