OCT angiography measured changes in the foveal avascular zone area after glaucoma surgery

Background/Aims To evaluate quantitative changes in the foveal avascular zone (FAZ) area after glaucoma surgery using swept-source optical coherence tomography angiography (SS-OCTA). Methods Fifty-four consecutive patients with primary open-angle glaucoma (POAG) who met the inclusion criteria and underwent unilateral glaucoma surgery to reduce intraocular pressure (IOP) between April 2018 and July 2019. Eyes underwent IOP-lowering glaucoma surgery and their fellow (non-surgical) eyes were included. OCTA of the macula was performed in both eyes before glaucoma surgery and 3 months postoperatively. Two blinded examiners reviewed the image quality. Within- and between-group comparisons of the FAZ area and correlation of the FAZ area with age, IOP, central sensitivity and clinical variables. Results The mean (+/- SD) age was 66.7 +/- 11.3 years. After surgery, the IOP and FAZ area significantly decreased from 22.1 +/- 9.5 mmHg to 10.3 +/- 3.5 mmHg and from 0.485 +/- 0.193 mm(2) to 0.446 +/- 0.174 mm(2), respectively (both p<0.001). Conversely, in the non-surgery group, the preoperative and postoperative mean FAZ areas (0.398 +/- 0.119 mm(2) and 0.396 +/- 0.110 mm(2), respectively) did not significantly differ (p=0.469). Change in the FAZ area significantly correlated with the preoperative FAZ area, preoperative foveal sensitivity and change in IOP (all p<0.05). Conclusions The FAZ area is decreased with IOP-lowering surgery in patients with POAG, and change in the FAZ area was significantly correlated with both preoperative foveal sensitivity and change in IOP.

Automated summary

The study evaluated quantitative changes in the foveal avascular zone (FAZ) area after glaucoma surgery, revealing a significant decrease in FAZ area with IOP-lowering surgery in patients with POAG. The change in FAZ area was significantly correlated with both preoperative foveal sensitivity and change in IOP.