Evaluation of peripapillary and macular vascular changes after trabeculectomy using OCT angiography

Purpose: To determine the microvascular changes in the optic nerve head and the macular area after trabeculectomy using OCT angiography Methods: In a prospective interventional case series, 50 eyes from 28 patients with uncontrolled IOP in spite of maximum tolerable medications were enrolled in the study. Patients with previous intraocular surgery were excluded from the study. By using OCT angiography vessel density in the radial peripapillary area and the macular area was evaluated. In addition RNFL thickness was measured preoperative and one month and 6 months after surgery. Results: Preoperative IOP was 23.2mmHg(SD=10.4), which decreased significantly to 10mmHg(SD=2) at six months after surgery. (P<0.0001) RNFL superior and inferior hemifield thickness was 71.6 (SD=28.1) and 71.3 (SD=26.2) micron before surgery, which has not changed significantly after surgery. 71.4 (SD=28.0) and 69.1 (SD=27.9) respectively (P> 0.05 for both) Radial PP circle superior Hemi Field vascular density was 39.6(SD=11.2) before surgery, which was decreased to 37.9 (SD=11.3) at one month after surgery (P<0.02) and increased significantly to 39.7 (SD=11.4) at 6 months after surgery. (P<0.02) Radial PP circle inferior Hemi Field vascular density was 38.9 (SD=10.2) before surgery, which was decreased to 36.9 (SD=11.6) at one month after surgery (P<0.003) and increased to 39.0 (SD=10.8) at 6 months after surgery. (P<0.05) The whole deep vessel density in macula was 46.6 (SD=5.4), which has not changed significantly 6 months after surgery. 47.1 (SD=5.4) (p<0.49) Conclusion: We observed a significant transient decrease in radial peripapillary vascular density at one month after trabeculectomy, but vessel density increased gradually and remained stable at 6 months after surgery.