Optical Coherence Tomography Observation of Gonio Structures during Microhook Ab Interno Trabeculotomy

Introduction. Intraoperative observation of ocular structures using microscope-integrated optical coherence tomography (iOCT) has been adopted recently. I report my initial feasibility assessment of iOCT for the incised trabecular meshwork observation during microhook ab interno trabeculotomy. Case Series. Both the nasal and temporal sides or either side of the trabecular meshwork/inner wall of Schlemm’s canal was incised more than 3 clock hours. After then, under observation using a Swan-Jacob gonioprism lens with the real-time 5-line scan mode, OCT images of the area were successfully acquired in 10 (83%) of 12 sides in nine eyes. Based on the appearance of the acquired images of the 10 sides, the trabeculotomy cleft could be classified into three incisional patterns, that is, six (60%) anterior-opening patterns (posterior-based flap), three (30%) middle-opening patterns (posterior- and anterior-based flaps), and one (10%) posterior-opening pattern (anterior-based flap), according to the predominant locations of the trabecular meshwork flaps. Conclusion. Intraoperative observation of the gonio structures including the trabeculotomy cleft was feasible using the RESCAN 700 in combination with a gonioprism.