October 2020


Device Focus
Exploring heads-up technology

by Ellen Stodola Editorial Co-Director

Dr. Ganesh performs standing phaco surgery using the heads-up technology.
Source (all): Sri Ganesh, MD

Heads-up technology offers surgeons a new approach in the OR instead of the traditional operating microscope. Two surgeons discussed their experience with the technology and how it compares to the tried and true method.
“In some regards, there’s very few things that can replicate or simulate true glass optics when you’re trying to do microscopic surgery,” said Robert Weinstock, MD. “For 100-plus years, optics have been refined by companies like Zeiss, Nikon, and Leica.” They have provided surgeons with an outstanding view of the surgical field, he said. Different light sources now inside microscopes can provide amazing optics to capture the surgical field in high resolution.
The problem, Dr. Weinstock said, is the surgeon has to conform to the device, looking through the oculars, putting their body in a position where they’re over the patient, potentially hunched or bending over awkwardly.
In addition, Dr. Weinstock said, optics, because of the working distance, make it such that when you operate under high magnification, it increases strain on the eyes, the convergence, accommodation, etc., which can cause pain and discomfort.
Current microscopes also only allow one person at a time to be able to see what’s going on, he said.
Enter the heads-up approach. Dr. Weinstock said he has extensive experience with this because he was one of the first surgeons globally to operate with the technology in 2008. He noted that he helped TrueVision develop this technology.
At first, it was rudimentary, had low-speed image capturing, and low resolution. But over the last decade, it has been refined to be a state-of-the-art device that provides a perfect image of the eye for surgeons to use, he said. Dr. Weinstock now uses the NGENUITY system (Alcon).
Sri Ganesh, MD, also has experience working with this technology. He first experimented with the TrueVision system and has also used the Alcon and Carl Zeiss Meditec technology. For about a year, he’s mainly been using the ARTEVO 800 (Carl Zeiss Meditec).
Dr. Ganesh noted that there’s familiarity among surgeons with a traditional microscope. “We have been training on it for years, and it’s just a matter of comfort using something for many years.”
Like any new system, he said, heads-up technology requires adaptation. However, he noted that this technology addresses one of the main disadvantages of the traditional microscope: ergonomics.
With the traditional microscope, you have to bend your neck when looking at the oculars, which can cause neck and shoulder pain. He noted that the distance between your eyes and hands are always fixed, so this could be challenging for both short and tall surgeons.

Features and how it compares to a traditional microscope

In terms of depth perception, Dr. Weinstock said this depends on the positioning of the 3D screen and also a bit on the surgeon’s brain. Other factors may include the diaphragm and the aperture system in the microscope. There are multiple ways to augment the depth of field, he said. “In general, I’ve noticed a greater depth of field and a more immersive type of experience by operating heads-up.”
Dr. Weinstock said that while earlier heads-up technology was a lower resolution system where you might notice a subtle lag and granularity, the latest technology has improved significantly. An example is the sensors in the 3D camera that capture the image coming
from the microscope, he said. The optics of the microscope are still used as a light source, but instead of going into your eyes, it’s going into a sensor, he said. These have evolved up to 4K sensors or higher, which is processed quickly by a sophisticated image processing system that eliminates any lag. “Most surgeons are not noticing any lag or loss of contrast or resolution when they operate through the current generation 3D systems,” he said.
Dr. Weinstock also called the ergonomics of heads-up technology “a whole game changer.” Study after study has been done, not just in ophthalmology, showing that the risk of work-related injury from microscopes is huge, he said, adding that 50–70% of microscopic surgeons at some point will suffer from acute or chronic back or neck injury relating to the position they’re in from operating for a long time.
“When a surgeon is operating, they’re frozen in one position,” he said, which can cause stiffness and the potential for the surgeon to lose concentration/focus.
Dr. Weinstock said comfort when you operate will allow you to operate longer, extend your career, and take less time off of work due to injuries. In addition, the ability to operate in that position may to lead to less surgical complications because you’re more comfortable, he said.
Dr. Ganesh commented that the heads-up technology offers the surgeon the option to operate while standing. He noted that sometimes a patient may have difficulty lying flat, and with this technology, he has performed surgery where the patient is essentially sitting upright.
When asked about the possibility of converting during surgery from the heads-up display to the traditional microscope, Dr. Weinstock said it’s possible, but he no longer finds it necessary. When the heads-up technology was newer, and the resolution was not as high and the quality of the image not as good, Dr. Weinstock used to have a beam splitter and could switch back and forth. “But in the current generation, when surgeons switch over to this, you can dive right in and take the oculars off and put the camera on,” he said. “Once you get used to it, you don’t go back.”
Dr. Weinstock added that guidance systems and overlays can also be used with this heads-up technology, though he doesn’t think these have evolved to their full potential yet in conjunction with this technology. “They’re all good, and they all have their roles, and I think that’s a lot of surgeon preference. I think that type of technology will continue to improve and be built into these scopes,” he said.
Dr. Ganesh did note some potential disadvantages of heads-up technology, mainly the amount of space it occupies in the OR. He added that he also likes to still use the traditional microscope for suturing, as he finds this is a slightly better and faster method.

Introducing the technology into the OR

Dr. Weinstock touted the benefits of heads-up technology for surgical staff. “It’s amazing for scrub techs to be able to see what’s going on and where I am in the case so they can anticipate my next move and see what I might need versus looking at a tiny monitor,” he said.
He added that it also helps keep staff engaged in the case and provides surgeons the opportunity to teach more.
Dr. Weinstock frequently has a fellow working with him. “There’s no way I could impart the knowledge and education without this system because I’m able to show them exactly what I’m doing,” he said. “They can stand right next to me or behind me and see what I’m seeing.” He added that it’s also beneficial when trainees are operating for him to be able to have easy access and see what is going on in the case.
Dr. Ganesh agreed that heads-up surgery offers advantages for teaching and observing purposes. “When observers are in the OR, they can wear 3D glasses and have the same view as the surgeon,” he said. “It’s an excellent teaching tool.”
He added that where he operates, they’ve begun to train other staff on how the system works as well, and it helps that they can appreciate all the surgical steps. There is a learning curve, he said, but it’s not long.

Other technologies

Dr. Weinstock mentioned that Beyeonics is developing a similar technology, though it is a helmet and headset. This offers an augmented reality view of the surgical field. Surgeons can see ahead of them, but they also can have other inputs put into the screen in front of them, he said. Dr. Weinstock said this product is near commercialization.

About the doctors

Robert Weinstock, MD

The Eye Institute of West Florida
Largo, Florida

Sri Ganesh, MD
Nethradhama Super Specialty
Eye Hospital
Bangalore, India

Relevant disclosures

: Carl Zeiss Meditec
Weinstock: Alcon, Carl Zeiss Meditec, Beyeonics


Ganesh: phacomaverick@gmail.com
Weinstock: rjweinstock@yahoo.com

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