3D Heads-Up Vitreoretinal Surgery

3D heads-up vitreoretinal surgery is entering prime time with Alcon and TrueVision’s Ngenuity system. A small camera box attaches to any microscope where the oculars usually are, and stunning views are displayed on a 55-inch HD 4K monitor. The surgeon wears polarized glasses or clip-ons, sits back in the chair, and operates looking heads-up at the screen. There are many advantages to operating with a 3D viewing system, but below are a few that I personally think are great features.

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The Ngenuity camera box attaches to the microscope where the main oculars conventionally have been.

(1) Low illumination surgery

Image manipulation is something we do all the time in our clinics with OCTs, photos, and fluoresceins. But now digital microscopy allows image enhancement of our surgical views intraoperatively. Among the various color settings and features, my favorite two are being able to adjust the gain, and the iris aperture size. We can decrease the endoillumination levels to 5-15%, and then either increase the gain or widen the aperture to allow more light to be detected. This permits the same views that we are used to, but the actual light pipe is much dimmer. I am less worried about phototoxicity, especially for macular cases.

(2) Ergonomics

Even as a young surgeon, you can start feeling the neck and back tension at the end of long OR days. I think that heads-up surgery has the potential to provide additional operating years to many of our careers. It feels great operating sitting back with full spinal support from the backrest of the chair. Watching my fellows operate is completely pain-free, because I can sit back with the chair turned to the screen, and do not have to lean forward awkwardly to get to the side scope while trying to avoid the foot pedals, microscope base, etc. Actively assisting with scleral depression takes a few cases to get used to since the screen is in the surgeon’s view, but it’s not a problem, and you can still look through the side scopes if it’s easier.

(3) Educational

Attendings can now see exactly what the fellows are seeing, and vice versa. It makes for a much more comfortable educational experience. For the first time, medical students and observers can actually see what’s taking place in the same detail as the surgeons, which makes surgical education much more immersive.

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Our second year fellow at Mass Eye and Ear, Dan Learned, is driving the Ngenuity system (left). I can see exactly what Dan is doing, while being able to sit back in my chair with full back support (right).

(4) OR synergy

The best surgical technicians anticipate every move that we make. Now that they can also see every detail of the case, there is no guesswork, and the techs can be even more engaged in the surgery to maximize their support.

(5) Beautiful videos

The files are currently saved as contiguous 10-minute clips. The file sizes are large, but they produce very high quality videos. Even if you use a mediocre microscope, it will blow you away, especially if you are using outdated recording systems. The edited videos do lose resolution compared to what you saw during the surgery on the HD monitor, and there is also some compression from the raw files, but the resultant videos will be much better quality than what most recording systems allow. The videos can be edited to be either 2D or 3D videos. Playback in 3D will require 3D monitors, or portable 3D viewers such as the Google Cardboard Viewer.

 

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The 55-inch HD 4K monitor is placed at the foot of the bed. The contrast and resolution are best appreciated in a dark room, and looking straight onto the screen.

(6) Image overlays

We’ve played around with uploading patient OCTs and fluoresceins into Ngenuity to allow viewing of the images intraoperatively. It was nice, but it’s a little cumbersome so we don’t routinely do this. In the near future though, the retinal image overlaying will become more streamlined, and future developments should see incorporation of real-time imagine modalities.


Yoshihiro Yonekawa, M.D.