A team of surgeons has successfully performed what they say is the world’s first robotic–assisted surgery inside the human eye.

They tested the approach in a trial involving six patients randomly assigned to robotic–assisted vitreoretinal surgery and six others who had standard manual surgery.

"The robot performed numerically better than the human in terms of creating fewer retinal hemorrhages, but the study was not powered sufficiently to show statistically significant results," said Dr. Robert MacLaren of the University of Oxford, U.K., who presented the results May 8 at the annual meeting of the Association for Research in Vision and Ophthalmology, in Baltimore, Maryland.

“Robotic technology is likely to allow us to do new operations that are currently beyond the capability of the human hand,” Dr. MacLaren told Reuters Health in an email. “A robotic system has huge advantages for operations under the retina or for operations in which a long and controlled procedure is required – for instance, when injecting gene therapy or cells under the retina.”

Co–author Dr. Marc D. De Smet, chief medical officer at Preceyes B.V. in Eindhoven, the Dutch company that developed the technology, said the robot allows for “10 times” more precision than the unaided human hand.

“This trial proves that the approach is safe, and also that it causes less trauma than standard surgery (a very early sign of efficacy)," he told Reuters Health by email.

All patients had surgery under general anesthesia to remove the internal limiting membrane or the epiretinal membrane. In the robot group, the surgeon operated a motion controller at the edge of the surgical field on the temporal side, controlling micromanipulations of the instrument through a valved 23G (gauge) trocar at the pars plana. In the manual group, the surgeon initiated a flap at the onset of a retinal peel.

The surgeon used chandelier illumination to help make the robotic surgery touch–free. The robot was able to hover directly over the membrane in 10–mcm or greater preset motion increments in the Z axis, enabling the instrument to engage the inner retina and lift a membrane flap. A Z–axis motion limit prevented the surgeon from accidentally advancing the instrument.

On average, it took 213 seconds to lift the membrane in the robotic surgery group and 130 seconds in the manual group. There were two retinal micro–hemorrhages and one retinal touch in the robot group, compared to five and two, respectively, in the manual group.

In all patients, the operation was successful and without complications, the researchers say.

The team is planning to combine robotic surgery with gene therapy in an upcoming clinical trial.

"The fine delivery of genes into the subretinal space is a goal to be mastered,” Dr. De Smet said. “The robot's inherent stability enables it to remain in place and be left as long as needed, with 10–micrometer precision. We can deliver a gene product at the rate the retina will tolerate, not as a function of our physiological limits at holding a needle in place for a prolonged period of time."

"As with pilots on commercial airlines, they guide the flight along the best possible path, but computers control all flight subsystems. In the same way, using robotics, the surgeon of the future will pilot surgery, but the actual surgery will be carried out by machines that have 10 times or more precision than is currently possible," he added.

The trial was funded by the National Institute for Health Research Oxford Biomedical Research Centre with support from Oxford University Hospitals NHS Foundation Trust. The university is collaborating with Preceyes B.V. to develop the device for gene therapy.

—Lorraine L. Janeczko