Purpose <p>To evaluate the utility of intraoperative optical coherence tomography (OCT) in filtration surgery using PRESERFLO^<b>®</b> MicroShunt.</p> Study design <p>Single-center prospective observational study</p> Methods <p>Filtration surgery using the MicroShunt was performed on 14 patients (15 eyes) diagnosed with open-angle glaucoma at our institution. The insertion pathway was created using a knife under intraoperative OCT guidance, and the position of the MicroShunt was verified after insertion. In cases of inadequate positioning, a new insertion pathway was created. Furthermore, the correct position was confirmed postoperatively using anterior segment OCT.</p> Results <p>In all cases, the real-time observation or replay playback of intraoperative OCT allowed for the visualization of the positional relationship between the device and surrounding tissues. This provided valuable assistance in determining the adequacy of the insertion pathway. In certain cases, the knife or inserted MicroShunt was in contact with the cornea or iris, leading to a revision of the insertion pathway. Regardless of the case, at the end of each surgery confirmation was made that the inserted MicroShunt was fixed in the proper position in the anterior chamber. Postoperative anterior segment OCT also revealed its presence in a similar position.</p> Conclusion <p>Intraoperative OCT is a valuable tool for ensuring a more secure insertion in filtration surgery using MicroShunt.</p>