Objective To investigate the pathogenesis of primary open-angle glaucoma. Methods The 85 patients with open-angle glaucoma were divided into 2 groups, including the high IOP group and the normal IOP group, and their data were compared with that of 24 normal persons. The changes of fundus fluorescein angiography and hemorheology and their relationship with TCM syndromes were studied. Results Compared with the normal group, the blood viscosity and hematocrit values at VH, VM, VI shear rate in the high IOP group and the normal IOP group were highly significantly different (P