NEW PRODUCT APPLICATIONS

OCT Upgrade Is the Next Innovation in Intraoperative Imaging

Optical coherence tomography device seamlessly integrates into the workflow.

BY KAREN APPOLD, CONTRIBUTING WRITER

Morrisville, NC-based Leica Microsystems offers EnFocus, an intrasurgical optical coherence tomography (OCT) upgrade solution for new and existing surgical microscopes. The device can be attached or removed within minutes.

The EnFocus OCT puts real-time, deep, and high-resolution OCT imaging directly into retinal surgery. “Visualization is now possible before, during, and immediately following surgical procedures,” says Eric Buckland, executive director, Bioptigen, Leica Microsystems. “The instrument is designed to deliver world-class imaging resolution, penetration depth, and image scan length. Surgeons can use existing retinal viewing systems, such as the Oculus BIOM, simultaneously with the EnFocus OCT.”

Justis P. Ehlers, MD, a vitreoretinal specialist in Cleveland, Ohio, and his research group served as a testing site for the EnFocus OCT prototype. “The biggest leap forward with this system compared to Bioptigen’s Envisu system for intraoperative imaging is the integration of EnFocus within the microscope’s optical path,” he says. “In the past, we had to stop surgery in order to take an OCT image. Now we can look through the microscope while simultaneously taking an OCT, allowing improved aiming and the potential for real-time OCT. It works into the surgical workflow more seamlessly.”

INNOVATIONS ABOUND

The EnFocus OCT was designed for intrasurgical imaging. Its unique objective-delivery design injects the OCT signal below the optics carrier —not through microscope oculars. This design maximizes OCT image performance, resulting in a widefield of view (up to 20 mm), with fully centered, true telecentric images, and independent OCT image zoom and focus control.

The EnFocus OCT quickly provides high-definition sub-surface images during critical procedures. Specifically, it offers fine axial resolution (≤4 μm) coupled with 2.5 mm image depth in tissue.

“This aid in visualization provides a new view of fine membrane structures injected directly into the surgical workflow,” Buckland says. “Unlike desktop OCT systems, image averaging is not practical with intrasurgical OCT. This places a premium on delivering the best native images. The EnFocus system enables the surgeon to monitor progress in real time, as well as capture and play back data for later review.”

A retinal surgeon can preserve an existing microscope’s surgical working distance through the use of the broadband 175-mm or 200-mm focal-length objective lenses integrated within the EnFocus OCT scanhead.

CLINICAL APPLICATIONS

The EnFocus is designed for both posterior and anterior surgeries. To date, intrasurgical OCT has been used prominently by retinal surgeons to visualize retinal detachments, epiretinal membranes, macular holes, and vitreomacular traction.

Dr. Ehlers and his research team have found that intraoperative OCT is quite valuable in surgical decision-making, including membrane-peeling cases, vitreous hemorrhage cases, and more complex procedures (eg, proliferative diabetic retinopathy). “In membrane-peeling cases, we have found that in 15% to 30% of cases, OCT has demonstrated something that the surgeon wasn’t expecting, and as a result the surgeon changed his or her approach,” he says.

By providing immediate feedback of the surgical anatomy in the operating room, Dr. Ehlers believes intraoperative OCT may shorten the learning curve for younger surgeons or surgeons looking to master new techniques.

EASY TO OPERATE

The EnFocus includes easy-to-use InVivoVue OCT image management software, which provides intuitive surgical planning and workflow management. The graphical user interface includes very wide OCT viewing windows, on-screen procedural pre-set modes, and customizable scan management. On-screen caliper measurements are available to measure and record structures of the retina with fine accuracy. An integrated Doppler visualization tool provides qualitative feedback regarding vascular blood flow.

The EnFocus OCT mounts fairly quickly onto the microscope. Its long optical and power cable allows flexibility for placing the device within the operating room; it could be used on both ceiling- and floor-mounted microscopes. Its modular design and mobile cart allow for flexible sharing between microscopes. RP