Intraoperative Optical Coherence Tomography Enables Noncontact Imaging During Canaloplasty

Here we describe intraoperative optical coherence tomography (iOCT) as a novel noncontact imaging tool for intraoperative monitoring and procedure evaluation during canaloplasty, as a nonpenetrating surgical technique to treat primary open angle glaucoma.

Retrospective case report of a patient (63 y, female), who underwent traditional canaloplasty, using a commercially available 840 nm OCT device, mounted to an operating microscope (Rescan 700). Main outcome measures were the intraoperative visibility of chamber angle structures and the ability to conduct surveillance of the surgical procedure through the prepared Descemet window, especially correct suture positioning and visible changes of the Schlemm canal after suture tensioning.

iOCT delivered high-resolution images during canaloplasty after deep sclerectomy through the prepared Descemet window. All structures of the chamber angle, including the Schlemm canal were visible. Moreover iOCT enabled intraoperative noncontact procedure monitoring and a direct control of the correct localization and changes of the Schlemm canal after suture positioning and tensioning.

iOCT seems to be a helpful intraoperative imaging tool during canaloplasty. iOCT allows for noncontact online evaluation of Schlemm canal localization and noncontact evaluation of suture tension. Shadowing of scleral tissue can be avoided by imaging through the routinely prepared Descemet window to visualize chamber angle structures including the implanted suture.