Observation of Gonio Structures during Microhook Ab Interno Trabeculotomy Using a Novel Digital Microscope with Integrated Intraoperative Optical Coherence Tomography

Abstract

Purpose. Observation of ocular structures using microscope-integrated intraoperative optical coherence tomography (iOCT) has been adopted. Using the novel digital ophthalmic microscope, ARTEVO 800 with iOCT, we tested the feasibility of trabecular meshwork (TM) imaging during microhook ab interno trabeculotomy, a minimally invasive glaucoma surgery. Methods. The nasal and temporal sides of the TM/inner wall of Schlemm’s canal were incised more than 3 clock hours in 14 glaucomatous eyes of 10 patients. To observe the trabeculotomy site, iOCT was performed with the real-time five-line scan mode under observation using a Swan-Jacob gonioprism lens. The success of the imaging and visibility of the trabeculotomy cleft and its incisional patterns (i.e., anterior, middle, or posterior pattern) were determined by reviewing the iOCT video files. Results. OCT images of the region of interest were acquired successfully in 100% of the 28 nasal or temporal sides in 14 eyes, although the trabeculotomy cleft was not visualized in four (14%) sides due to blockage of the OCT signal by a blood clot. Based on the predominant locations of the TM flaps in 24 of the acquired images, the trabeculotomy clefts were classified as anterior incisional patterns in 13 (54%), middle incisional patterns in nine (38%), and posterior incisional patterns in two (8%). Conclusion. Intraoperative imaging of the gonio structures including the trabeculotomy cleft was feasible using the ARTEVO 800 with iOCT in combination with a gonioprism.

One-year outcomes of microhook trabeculotomy versus suture trabeculotomy ab interno

“…During microhook surgery, intraoperative OCT visualized the trabeculotomy cleft. Ishida et al [ 14 ] identified three incisional patterns (anterior-opening, middle-opening, and posterior-opening), according to the predominant locations of TM flaps. The anterior-opening pattern was reportedly predominant.…”

Clinical applications for intraoperative optical coherence tomography: a systematic review

“…Only three studies describing iOCT use during ab-interno trabeculotomy met the inclusion criteria for this review (see Supplementary Table 7). In all three studies the authors reported that cleft and incision patterns could be observed on the OCT image after trabecular meshwork tissue removal, thereby providing an indication of the surgery's success [120][121][122]. Notwithstanding, all three studies noted that image acquisition was challenging and they needed a gonioprism lens for visualizing the anterior chamber angle.…”

Optische Technologien, digital unterstützt: Operationsmikroskop – quo vadis?

“…Especially with the integration of intraoperative OCT, high-resolution image slices can be superimposed on the image of the surgical microscope in the eyepiece or on the screen almost as realtime information [20], so that delicate structures including depth information can be visualised without interrupting the surgical workflow [21]. The full integration of OCT into a microscopeboth as preoperative information as well as ongoing screeninglets the surgeon focus on the patient and the operation.…”