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Rise of the machines

Robots add an extra dimension to retinal surgery, creating new possibilities

Roibeard O’hEineachain

Posted: Friday, September 1, 2017

Continuing refinements in engineering and the increasing capabilities of computers have given rise to robotic devices designed to manipulate surgical instruments within the eye. These new robotic systems offer the promise of allowing the performance of previously almost impossible procedures, while also adding a degree of safety and simplicity to the more common procedures.

Several teams around the world have been developing these new surgical systems, which range from more or less mechanical devices to computer-controlled systems with precision in the micron range. The system that is furthest advanced in terms of clinical use is the R2D2, short for robotic retinal dissection device, which was developed by Preceyes BV, a medical robotics company based at the University of Eindhoven, The Netherlands.

Using the new robotic system, Robert E 
MacLaren MD, PhD, Professor of Ophthalmology at the University of Oxford, UK, performed the first ever robot-assisted operation inside the eye in September 2016. The procedure involved the removal of an epiretinal membrane from the eye of a 70-year-old man with a macular hole. In an interview with EuroTimes, Dr MacLaren noted that the surgical robot added a new dimension to retinal surgery.

“The ability to limit the forward movement vertically – in the ‘z axis’ – provides a unique aspect to vitreoretinal surgery that we have not seen before with the manual approach. We can see the ‘x-y’ movements quite easily with conventional surgery, but we are still dependent on seeing retinal touch to know how deep we are. This is a critical factor that has only now become important for subretinal approaches, such as with retinal gene therapy. The robot has a huge advantage in this regard,” he said.

INCREASED SAFETY
Following the groundbreaking surgery, Dr MacLaren and his associates carried out a randomised controlled trial in which they performed epiretinal membrane removal in six patients with standard surgery and six patients with the R2D2 unit. They found that there was no statistically significant difference between the two approaches in terms of safety.

However, five of the patients in the conventional surgery group had micro-haemorrhages, compared to only two patients in the robotic surgery group. There were also two instances of retinal touch in the conventional surgery group but only one such instance in the robotic group.

“The trial wasn’t really powered to show efficacy but there were clearly fewer instances of trauma and touching the retina in the robot group. The surgery in the robot group took longer to do, particularly in the first cases, because obviously we were going very carefully. Things went more quickly in our last patients,” Dr MacLaren said.

The controller of the robotic system is essentially a pen suspended from a frame in such a way that, as the surgeon moves it, the motion is translated in a scalable fashion to the movement of the surgical instrument inside the eye, with a precision of 10 microns. Unlike manual surgery it is unaffected by any tremor of the surgeon’s hand, Preceyes’ Chief Medical Officer Marc de Smet MD, PhD told EuroTimes.

“We can theoretically adapt it to virtually any kind of existing instrument for retinal surgery. We are in the process of developing the software for a range of procedures, which would essentially simplify the vitreoretinal surgeon’s life by taking away some of the tedious and boring aspects of the surgery, and also take over those which require very high precision in surgery,” said Dr de Smet, MIOS, Lausanne Switzerland.

He added that unlike manual surgery, if the surgeon pauses to consider his or her next move, the instrument will remain in place until the procedure is resumed. Similarly, because of the computerised navigation the system provides, when exchanging surgical instruments, it can return to almost the exact same location as it was before.

“Most of the surgeons that try our system will tell you that one of its advantages is that it removes stress, because you don’t have to concentrate as much on avoiding steps that could potentially lead to complications,” 
Dr de Smet said.

Another aspect of robotic and information technology that has made significant advances in recent years is artificial intelligence. Artificial intelligence enables machines to learn through training and experience. That raises the question of whether some day robots like the Preceyes device will be able to perform entire procedures autonomously. However, Dr MacLaren says he thinks that there would always be a role for human surgeons.

“It may become technically possible, but I think we will always need someone to monitor what the robot does. We named our study the ‘robotic retinal dissection device’ (R2D2) trial, but even R2D2 was always under the watchful eye of a Jedi master,” he added.

Robert E MacLaren MD, PhD: enquiries@eye.ox.ac.uk
Marc de Smet MD, PhD: marcdesmet@preceyes.nl