Evaluation of peripapilleries and macular vessel densitychanges after trabeculartomy by optical coherenstomography angiography

Purpose: To evaluate the effect of lowering intraocular pressure (IOP) on fovea avascular zone (FAZ), peripapillary and macular vessel density (VD) by optical coherence tomography angiography (OCTA) in patients with open angle glaucoma after trabeculectomy. Materials and Methods: Twenty eyes of 20 patients with primary open angle glaucoma (POAG) or pseudoexfoliative glaucoma (EG) who were followed up and underwent trabeculectomy were included in our study. OCTA scans were performed before glaucoma surgery, and at 1-month, 3-month and 6-month, post-operatively. OCTA, AngioVue (Optovue Inc, Fremont, CA) software was used to analyse the FAZ, peripapillary VD, macular superficial capillary plexus (SCP) and deep capillary plexus (DCP) VD. The parameters of the preoperative and postoperative controls were compared statistically. A p value less than 0.05 was considered statistically significant. Results: Mean age of our patients was found 63.8 (53-72). Twelve of the patients (60%) were diagnosed with POAG and 8 (40%) with EG. Mean IOP values were measured as 22.38 ± 2.36 mmHg preoperatively and 14.94 ± 2.38 mmHg in the postoperative sixth month (p <0.001). There was no significant change in OCTA optic disc and macular YCP VD values at the end of the sixth month. In macular DCP parameters; all image macular VD (TIM- VD), foveal VD (F-VD), parafoveal VD (PAF-VD) and perifoveal VD (PEF-VD) values increased statistically (p = 0.003; p = 0.026; p = 0.006; p = 0.004). There was a statistically significant decrease in FAZ-A and FAZ-P; and a significant increase was found in FD (p = 0.026; p = 0.049; p = 0.005). Conclusions: In our study, we found that reducing IOP by trabeculectomy did not affect the microcirculation of the peripapillary region and macular YCP, while there was a significant increase in the DCP parameters of the macular region. It was thought that the decrease in the FAZ region in the postoperative period, especially in the first month, might be related to the increase in DCP vascularization. We concluded that OCTA could be used as a potential method evaluating FAZ and macular DCP perfusion after glaucoma surgery. Keywords: optical coherence tomography angiography, glaucoma, trabeculectomy, vessel density