Effect of Surgical Intraocular Pressure Lowering on Peripapillary and Macular Vessel Density in Glaucoma Patients: An Optical Coherence Tomography Angiography Study

PURPOSE: To measure the influence of surgically induced intraocular pressure lowering on peripapillary and macular vessel density in glaucoma patients using optical coherence tomography angiography. METHODS: Twenty-one eyes of 21 patients with open-angle glaucoma scheduled for filtering surgery were enrolled prospectively. Using optical coherence tomography angiography, vessel density was quantified within the peripapillary and macular regions, before and 1 month after filtering surgery. Change in vessel density was calculated for all analyzed areas. RESULTS: One month after surgery, the mean intraocular pressure reduction was 44.2%±4.8% (range, 15.2% to 77.1%). The mean change in vessel density for the whole peripapillary area was 0.065±0.88% (P=0.788). In the macular region, the mean change in vessel density was -0.022%±0.691% (P=0.405) with significant changes only within the inferotemporal area of patients with predominantly superior visual field defects (-1.86%±1.43%, P=0.024). CONCLUSIONS: Optical coherence tomography angiography allowed very limited measurement of intraocular pressure lowering-induced changes on the vessel density of the peripapillary and macular regions in glaucoma patients.