Live volumetric (4D) visualization and guidance of in vivo human ophthalmic surgery with intraoperative optical coherence tomography

Abstract

Minimally-invasive microsurgery has resulted in improved outcomes for patients. However, operating through a microscope limits depth perception and fixes the visual perspective, which result in a steep learning curve to achieve microsurgical proficiency. We introduce a surgical imaging system employing four-dimensional (live volumetric imaging through time) microscope-integrated optical coherence tomography (4D MIOCT) capable of imaging at up to 10 volumes per second to visualize human microsurgery. A custom stereoscopic heads-up display provides real-time interactive volumetric feedback to the surgeon. We report that 4D MIOCT enhanced suturing accuracy and control of instrument positioning in mock surgical trials involving 17 ophthalmic surgeons. Additionally, 4D MIOCT imaging was performed in 48 human eye surgeries and was demonstrated to successfully visualize the pathology of interest in concordance with preoperative diagnosis in 93% of retinal surgeries and the surgical site of interest in 100% of anterior segment surgeries. In vivo 4D MIOCT imaging revealed sub-surface pathologic structures and instrument-induced lesions that were invisible through the operating microscope during standard surgical maneuvers. In select cases, 4D MIOCT guidance was necessary to resolve such lesions and prevent post-operative complications. Our novel surgical visualization platform achieves surgeon-interactive 4D visualization of live surgery which could expand the surgeon’s capabilities.

Review of intraoperative optical coherence tomography: technology and applications [Invited]

“…A separate study corroborated these findings and reported that MIOCT altered decision-making in 41.9% of procedures [124]. Lastly, Carrasco-Zevallos et al first reported live 3D (4D) MIOCT of human retinal surgery [122,145,146], and this custom swept-source OCT system was demonstrated to produce B-scans of comparable quality to HHOCT imaging during surgical pauses [182]. In addition, 4D MIOCT provided enhanced volumetric feedback during live surgery, which facilitated recognition of 3D structural alterations after surgical intervention and enabled more complete visualization of surgical maneuvers (Fig.…”

“…This feature allowed a densely-sampled OCT scan to be re-centered to the site of interest in realtime after lateral translation of the microscope relative to the surgical field. Several MIOCT systems also employed independent OCT refocusing mechanisms in case the surgical field was shifted outside the OCT focus plane [117,121,122]. The electrically-controlled tunablefocus lens incorporated in [117] could also enable automatic focus adjustment.…”

“…6(a)). Using the manual tracking feature described in Section 3.1, some of these systems also allowed the B-scans to be manually tracked to the tip of instruments during surgical maneuvers [118,121,122]. Alternatively, multiple (3-5) parallel B-scans spanning the site of interest could be acquired and displayed simultaneously to monitor motion orthogonal to the B-scan axis [123,132] (Fig.…”

“…The imaging protocols of 4D MIOCT for human ocular surgery were first determined during preliminary mock surgical trials. In these, the volumetric OCT visualization of commonly used instruments for human ocular surgery was characterized (see Supplementary Information of [122]) (Fig. 7(b)).…”

“…This system, together with a custom stereoscopic HUD [144], was translated to the human operating suite in 2015 [122,145,146] and has been used in over 150 human ocular surgeries to date. Using an MIOCT scanner designed for imaging of human ocular surgery [71], the researchers employed a 1040 nm swept-source OCT system running at 100 kHz Ascan rate, which was 3-5 times faster than previous intraoperative OCT systems used in human ocular surgery.…”