Visualising the future

[caption id="attachment_11377" align="alignleft" width="1024"] Pravin Dugel using the TrueVision 3D operating system. Heads-up surgery. Courtesy of Perry Athanason/Retinal Consultants of Arizona[/caption] Digital imaging technologies now entering the clinic represent a revolutionary step forward that will allow vitreoretinal surgeons an unprecedented degree of three-dimensional resolution and depth of focus. EuroTimes gets a close-up look at intraoperative digital imaging techniques now in use and those in the pipeline. The development of digitally assisted vitreoretinal surgery (DAVS) follows up on tremendous innovations in micro-incision vitrectomy surgery (MIVS) developed by pioneering surgeon Claus Eckardt. Those developments led to faster and more efficient surgery and better outcomes compared to what came before. Digital visualisation systems involve special high-resolution 3D video cameras attached to the traditional operating microscope. The camera feeds images to a large, high-resolution 4K OLED flat-panel display. The surgeon and team members wear 3D glasses or head-mounted displays while watching the display. TrueVision 3D Surgical was a pioneer in intraoperative ophthalmic digital imaging. It found its first applications in anterior segment surgery some 10 years ago. The intervening years have seen a steady improvement in resolution and depth of focus. This culminated in an agreement with Alcon, leading to the NGENUITY 3D Visualization System (Alcon). “The ability to do vitreoretinal surgery with TrueVision at the kind of resolution we need has been fairly recent. I’ve been using it exclusively for three years now. “I like it for many reasons. It is a tremendous teaching tool, and the entire staff is in tune with you. I also like that everything is bigger, the resolution is better, the depth of focus is better, you are always in focus as you operate,” Pravin Dugel MD, Retinal Consultants of Arizona, Phoenix, US, told EuroTimes. Digital visualisation allows the surgeon to do some things not possible before. For example, it is possible to reduce the amount of illumination significantly during surgery, sparing the retina any unneeded light exposure. Digital manipulation can also help in cases of vitreous haemorrhage and other situations where colour filtering can improve visualisation. Proponents of 3D visualisation systems also cite the importance of ergonomics. The surgeon is relieved of the constant stress on neck, back and shoulders that accompany the use of conventional operating microscope over a lifetime. “This is very important. This is a major cause of morbidity for our profession. If you are able to do your surgery while not being in pain, you will likely do a better job, and likely have a longer career,” commented Dr Dugel. Another 3D imaging system, developed by Sony, also allows the surgeon to capture, record, and display 3D video during ophthalmic microsurgery. The system includes a HD 3D camera system, a 3D/2D video recorder and 4K high-resolution monitors. The world of intraoperative retina surgical imaging is evolving rapidly. A new system, BeyeOnics, borrows from the heads-up displays used by fighter pilots. This brings a level of augmented reality, as the surgeon wears a head-mounted helmet that provides an operating image, as well as overlays of OCT and other information. This new approach offers several advantages, according to Anat Loewenstein MD, Professor of Ophthalmology, Sackler Faculty of Medicine, Tel Aviv University, Israel. Firstly, it is more comfortable, since the surgeon’s head does not need to be attached to the microscope. Secondly, there is potential to see real-life input from OCT, fluorescein angiography etc., which would be of great benefit to the surgeon. Finally, having better resolution and the ability to control multiple parameters during surgery has many possible benefits for the surgeon, she told EuroTimes. “We have performed several surgeries to evaluate image quality, comfort of use and basic functionality. After the surgeries’ success, this year we are now performing complicated surgeries like ERM peeling and retinal detachment.” Indeed, Dr Loewenstein believes this approach represents a significant step forward from current technology. “First, the displayed image adjusts to the positioning of the surgeon’s eye, providing high-quality central and peripheral images. This eliminates the traditional microscopic pinhole view or the necessity to be fixed to a 3D monitor. The displayed image goes with the surgeon gaze direction, so no matter where I look at and no matter what is the orientation of the OR, I see a clear image. Due to the nature of the head display, the image that is displayed is true 3D the same as in a microscope, unlike 3D monitors,” she explained. The BeyeOnics system also has the capability to present an unlimited number of virtual screens. This makes it possible to see at the same time a large virtual display of the magnified image and next to it important data like patient retina imaging from OCT and other sources. “Maybe the most important, the system provides the ability to overlay external data like OCT in real-time in the surgical field and incorporates digital icons that provide reference to position and orientation on the magnified image. The technology tracking and real-time mapping will allow surgical tools to be visualised through blood and tissue, providing accuracy where the surgeon has no direct vision.” “I have no doubt that the use of digital visualisation will become ubiquitous, in our field. We will look back and say this was a decisive time. We’re not going to be using analogue microscopes in the future. Systems now in development will couple the imaging information with informatics, which will open up a new range of possibilities. This is just the beginning,” stressed Dr Dugel. Pravin Dugel: pdugel@gmail.com Anat Loewenstein: anatl@tlvmc.gov.il