Microvasculature Recovery Detected Using Optical Coherence Tomography Angiography and the Rate of Visual Field Progression after Glaucoma Surgery

PURPOSE: We evaluated microvascular changes using optical coherence tomography angiography (OCT-A) in glaucoma patients who underwent glaucoma surgery. METHODS. The macula and optic nerve head were imaged using an OCT-A device at one day before surgery and at one week, one month, three months, and six months after surgery. Measurements of vessel density (VD) were made in the intradisc region and macula, and the area of the foveal avascular zone (FAZ) was measured in both superficial and deep vascular layers. A mean deviation (MD) slope value of < −1.0 decibel/y was considered to be indicative of VF progression. RESULTS. A significant increase in VD was observed postoperatively in the deep vascular layer of the intradisc area (P < 0.001), and a significant decrease in the FAZ area was evident in the deep vascular layer (P = 0.018). An increase in the intradisc deep VD (17.48% ± 5.63%) was statistically significant in glaucoma eyes without progression, compared with those with progression (−1.27% ± 2.19%). Worse preoperative MD of the VF (P = 0.006), lower preoperative intradisc VD (P < 0.001), and fewer changes in the intradisc deep VD after surgery (P < 0.001) were significantly associated with MD slope. CONCLUSIONS. We found deep VD changes in the laminar region of the optic nerve head and the macular area at up to postoperative one month after glaucoma surgery. An increase in the deep VD in the laminar region was beneficial to VF progression in glaucoma patients after surgery.