Evaluation of peripapillary and parafoveal vessel density in primary open angle glaucoma patients undergoing non-penetrating deep sclerectomy procedure

Abstract

Glaucoma is still not well understood as the most common cause of irreversible blindness globally. Vascular problems in the development and progression of glaucoma have been the focus of researchers for decades. The present study evaluated peripapillary and parafoveal vessels using OCT angiography before and after deep sclerectomy surgery in primary open-angle glaucoma and glaucoma secondary to pseudo-exfoliation. Materials and Methods: In this case series study, patients with POAG referred to specialized and sub-specialized clinics of Tabriz Nikukari Hospital were selected, and after excluding patients eligible for exclusion criteria, they underwent base OCT angiography. Then, non-penetrating deep sclerectomy surgery was performed for eligible patients, and one month after the operation, they underwent IOP measurement, fundus examination, and visual acuity, and six months after the operation, they underwent OCTA and the mentioned examinations. Results: Twenty-two patients with POAG who underwent deep non-penetrating sclerectomy underwent OCTA before and after surgery. The mean age of the patients was 66.90±11.65 years. The mean initial IOP of patients was 24.86 mmHg and decreased significantly after surgery. After surgery, the mean IOP, one month after and six months after, was 8.18 mmHg, 8.55 mmHg, and 10.23 mmHg, respectively. Significantly, mean postoperative MD values increased (-15.44±9.55 dB vs. -13.6±7.76 dB; p=0.038), but there was no difference in preoperative and postoperative PSD values. Peripheral vascular density in the Inferior Temporal (33.73±15.90% vs. 36.50±14.47%; p=0.002) and Temporal Superior (42.49±9.32% vs. 51.25±11.83%; p=0.003) increased significantly after surgery. In other areas, there was no statistically significant difference between before and after surgery results. RNFL thickness after surgery in Nasal Superior (64.42±22.96 μm vs. 70.47±21.16 μm; p=0.045), Nasal Inferior (57.42±18.42 μm vs. 66.14±16.54 μm; p=0.012), Inferior Nasal (76.86 ± 33.50 μm vs. 81.68±35.35 μm; p=0.011) increased significantly.