Fluctuation of Chorioretinal Blood Flow Detected by Optical Coherence Tomography Angiography and Glaucoma Progression

Purpose: To investigate the role of chorioretinal blood flow fluctuation in the optic nerve head and macular area on glaucoma progression.Methods: This prospective, observational study enrolled a total of 92 eyes from 75 patients with open-angle glaucoma who had more than twice exams using optical coherence tomography.Vessel density (VD) was measured from optic disc images of the superficial and deep vascular layers, and the root mean square error was estimated as a measure of the VD fluctuation.According to the mean and standard deviation of chorioretinal deep vessel density fluctuation (DVDF) value, participants were categorized into high or low DVDF parapapillary area groups.Factors associated with the slopes of mean deviation (MD) and visual field index (VFI) were analyzed.Results: There was a significant correlation between DVDF in the parapapillary area and glaucomatous progression for visual field (VF) parameters such as MD, pattern standard deviation, and VFI slopes (p = 0.001, 0.021, and < 0.001, respectively).The group with greater DVDF demonstrated faster glaucomatous progression than the lower DVDF group for MD and VFI slopes (p = 0.033 and 0.027, respectively).Linear regression analysis showed DVDF in the parapapillary ( = -0.398,p < 0.001) and macular areas ( = -0.261,p = 0.016) significantly associated with the MD slope of VF.Conclusions: VD fluctuation of the deep vascular layer around the optic disc has a significant relationship with VF progression in glaucoma patients, which might indicate blood flow instability around the optic nerve head.