To measure the functional reorganization pattern of primary open-angle glaucoma (POAG), functional connectivity density (FCD) maps were applied with resting-state functional MRI.Our hypothesis is that reorganization of functional connectivity in visual cortices and remote visual correlated brain areas can be detected in POAG patients. In this study, twenty-one patients and twenty-two age- and gender-matched healthy controls were evaluated by 3T MRI using resting-state blood oxygenation level dependent imaging. The subjects in both groups underwent a thorough history and physical examination including an ophthalmology examination. After the preprocessing steps, the long-range and short-range FCD maps derived from degree centrality calculation were calculated. A two-sample t-test was conducted to show the difference between the two groups. The threshold was set at p-values < 0.01 using Monte Carlo simulations (corrected, AlphaSim program, single voxel P=0.01, 10000 simulations, FWHM is estimated by software, cluster connection radius r=5 mm, calculation with a GM mask, resolution=3 mm × 3 mm × 3 mm voxel size).Compared with normal controls, POAG patients showed decreased long-range FCD values in bilateral occipital visual cortices and left precentral gyrus, and decreased short-range FCD values in bilateral occipital visual cortices and cerebellum posterior lobes. Moreover, POAG patients showed increased long-range and short-range FCD values in bilateral insula and cingulate gyrus, and increased short-range FCD value in bilateral inferior parietal lobe.FCD is a voxel wise data-driven method based on fMRI, reflecting the complex connectome of brain 1. The decrease of short-range FCD in occipital lobes indicates that the neural connectivity in the visual cortices reduced. And the decrease of long-range FCD of occipital lobes indicates impaired connections between visual cortices and remote voxels. Precentral gyrus is somatosensory cortex which is related with primary visual cortex, and previous glaucoma MRI study also reported decreased spontaneous activity in this area 2. These findings are compatible with vision loss caused by POAG. The cingulate gyrus and inferior parietal lobe belong to default mode network, which receive intrinsic information from early visual cortex and shows reduced response to visual stimuli 3. Thus, the increased FCD of DMN components may be associated with the decrease FCD in visual cortices. These findings suggested the intrinsic information delivery in visual cortices and DMN changed in POAG patients.This study demonstrates POAG can induce reorganization of brain function in multiple brain regions, including visual cortices and DMN.