Four-dimensional Microscope-Integrated Optical Coherence Tomography to Visualize Suture Depth in Strabismus Surgery

Abstract

The authors report the use of swept-source microscope-integrated optical coherence tomography (SS-MIOCT), capable of live four-dimensional (three-dimensional across time) intraoperative imaging, to directly visualize suture depth during lateral rectus resection. Key surgical steps visualized in this report included needle depth during partial and full-thickness muscle passes along with scleral passes. [J Pediatr Ophthalmol Strabismus. 2017;54:e1-e5.].

Conflict of interest statement

Author Conflicts of Interest: At the time of this work, Dr. Izatt was Chairman and Chief Scientific Advisor for Bioptigen Inc., and had corporate, equity, and intellectual property interests (including royalties) in this company. Dr. Toth receives financial support from Alcon, Bioptigen, and Genentech and has an intraoperative imaging patent with Duke University. Dr. Kuo has an imaging algorithm patent licensed by Duke to Bioptigen, which is unrelated to the present work. For the remaining authors no conflicts were declared.

Copyright 2017, SLACK Incorporated.

Figures

FIGURE 1. Live visualization of partial thickness suture placement into rectus muscle as seen with swept-source microscope-integrated optical coherence tomography (SS-MIOCT)

SS-MIOCT 3D volume (left) with a white box demarcating its corresponding 2D B-scan (middle) and the standard surgical microscope view (right) showing the needle tip (blue arrow) at the surface interface of the lateral rectus muscle (A), within – but not beyond – the thickness (green bracket) of the muscle (B), and exiting the muscle (C) with the lowest point of the needle remaining within the thickness of the muscle. The suture (pink arrow) does not extend beyond the thickness of the muscle (D). The depth of the needle and suture relative to the muscle is much more easily visualized in the 3D volumes and 2D B-scans compared to the standard surgical microscope views (A-D). The suture needle can artifactually appear discontinuous due to different refractive indices of air and tissue. In all SS-MIOCT images, the red scale bar in the 2D B-scan measures 1 mm laterally and the blue scale bar measures 1 mm axially.

FIGURE 2. Live visualization of a full thickness pass through one pole of the rectus muscle (locking bite) as seen with swept-source microscope-integrated optical coherence tomography (SS-MIOCT)

SS-MIOCT 3D volume (left) with a white box demarcating its corresponding 2D B-scan (middle) and the standard surgical microscope view (right) showing the needle tip (blue arrow) at the surface interface of the lateral rectus muscle (A), progressing beyond the thickness (green bracket) of the muscle (B), and exiting on the other side of muscle (C). The depth of the needle relative to the muscle is much more easily visualized in the 3D volumes and 2D B-scans compared to the standard surgical microscope views (A-C). The suture needle can artifactually appear discontinuous due to different refractive indices of air and tissue. In all SS-MIOCT images, the red scale bar in the 2D B-scan measures 1 mm laterally and the blue scale bar measures 1 mm axially.

FIGURE 3. Live visualization of a scleral pass as seen with swept-source microscope-integrated optical coherence tomography (SS-MIOCT)

SS-MIOCT 3D volume (left) with a white box demarcating its corresponding 2D B-scan (middle) and the standard surgical microscope view (right) showing the needle tip (blue arrow) at the muscle insertion site (green arrow) at the surface interface with the sclera (A), within the thickness (yellow bracket) of the sclera (B), and exiting the sclera (C) with the lowest point of the needle and the suture (D) roughly 40% deep within the thickness of the sclera. The depth of the needle and suture relative to the sclera is much more easily visualized in the 3D volumes and 2D B-scans compared to the standard surgical microscope views (A-D). The suture needle can artifactually appear discontinuous due to different refractive indices of air and tissue. In all SS-MIOCT images, the red scale bar in the 2D B-scan measures 1 mm laterally and the blue scale bar measures 1 mm axially.