Intraoperative OCT (iOCT) For Canaloplasty

Abstract

Purpose: : Evaluation of a new surgical microscope-mounted OCT-Camera (iOCT) for intraoperative diagnosis and assistance in canaloplasty and comparison with postoperative results.

Methods: : 9 patients with (open angle) glaucoma were examined with the iOCT (MOELLER-WEDEL and OptoMedical Technologies, Germany) during routine canaloplasty surgery using a microcatheter (iTrack 250A, iScience Interventional, USA), viscodilatation and placement of two 10-0 Prolene sutures. Shape and size of Schlemm’s canal was measured and compared to postoperative performed Slitlamp adapted OCT (SL-OCT, Heidelberg Engineering, Germany). Acquisition time was 10000 A-scans/s. Image stacks, en-face OCT and 2D-real time imaging with additional volume scans of the procedures were recorded.

Results: : OCT-Camera enabled simultaneously real-time OCT imaging of catheterization of Schlemm’s canal. Scleral incisions, preparation of Descemet’s window were analyzed in real-time and reconstructed in 3D and 2D over time. Descemet’s window could be visualized in high-resolution after surgical preparation. Morphological evaluation with SL-OCT revealed either a round or wedge-shaped pattern of Schlemm’s canal. Mean overall suture tension grade was 2.2 (SD 0.6) analyzed by SL-OCT after canaloplasty.

Conclusions: : iOCT enables intraoperative high-resolution OCT imaging of Schlemm’s canal during canaloplasty. Intraoperative OCT is eligible for suture tension grading and imaging of morphology of Schlemm's canal and enables a direct intraoperative control of the intended suture traction. iOCT has the potential to become a new technological tool in different applications particularly in glaucoma surgery.

Keywords: anterior segment • imaging/image analysis: clinical • clinical (human) or epidemiologic studies: systems/equipment/techniques