Automated devices may soon be used for

Robotic surgery

Robotic tools and systems hold promise for targeted drug delivery within the eye. Dermot McGrath reports

“This is interesting in ophthalmology because it allows us to build tools that are much smaller and more flexible than conventional rigid tools for increased safety,” he said.

Possible applications for the catheter include subretinal delivery of drugs, gene therapies, or stem cells for retinal regeneration, autonomous navigation of a laser tool for treating diabetic retinopathy (DR) or safer epiretinal membrane peeling. “For drug delivery, this tool would allow the surgeon to precisely navigate to a desired location, hold the device in place, monitor it with OCT and then create this subretinal bleb into which therapies are injected,” he said.

For DR treatments, the catheter could be connected to a laser and steered to multiple points on the retina to perform a type of targeted photocoagulation treatment.

Another more futuristic application of the technology is the deployment of ocular microrobots – tiny, untethered devices that can be controlled inside the eye using magnetic forces.

“This could be used for many applications, including loading drugs, by steering it to a desired location and performing slow release of the drugs before it is retrieved from the eye,” he said. Samuel Charreyon: samuelch@ethz.ch A lthough eye surgery is currently lagging behind other fields of medicine in the use of robotic technology, the indications are that automated devices may soon be deployed for a range of applications such as intravitreal injections, epiretinal peeling or targeted drug delivery inside the eye, Samuel Charreyon MSc told delegates attending a symposium of artificial intelligence at the 37th Congress of the ESCRS in Paris, France.

“We have seen two decades of research in robots for eye surgery but there is only one robot that has so far been approved for commercial use and it still needs to prove that it is useful enough to be adopted for standard use in ophthalmology. So, while there is clearly some way to go in eye surgery robotics in general, we are now seeing some interesting technological solutions emerging from the lab that may have a role to play in the ophthalmic field in the near future,” he said.

There is a clear case to be made in terms of robotic surgery filling an unmet need in ophthalmology, particularly given the miniscule scale of the tissue structures encountered, said Mr Charreyon, a researcher at the Multi-Scale Robotics Lab at the ETH Zurich University in Switzerland.

“Eye surgery requires phenomenal dexterity where we are talking about precision needs that are measured in microns. Hand tremor is a real concern for the precision and accuracy of tissue manipulation. Robotics can offer increased dexterity and stability, and possibly also some sensing and feedback to be given to the surgeon,” he said.

He explained that robotic systems for surgery fall into two broad categories in terms of control paradigms: co-manipulation and tele-manipulation. The former approach is where the surgeon physically manipulates the robot, while in the latter scenario the surgeon is completely decoupled from the robot and interacts with it through a console or joystick. The first approved robotic device on the market, the Preceyes Surgical System, has been successfully deployed to perform epiretinal peeling on human patients. Earlier this year the device received CE mark approval to assist surgeons during vitreoretinal surgical tasks under local or general anaesthesia.

Another company, Ophthorobotics AG, has been focusing its attention on intravitreal injections, developing a fully automated system for safe and highly precise injections into the eye, noted Mr Charreyon.

The technology utilises specific sensors to identify and track patients’ eyes, performs automatic intravitreal injections, and features a sterile laminar airflow for reduced risk of infection. Patients can be prepared by the nursing staff, and the injections are remotely controlled and monitored by the treating physician from another examination room or office, allowing for a larger patient throughput.

“The demand for intravitreal injections has increased over the past 10 years due to the availability of new drugs, but also an ageing population. This type of system will potentially increase throughput for clinics while increasing the comfort of the patients and decreasing the cost of care,” he said.

Another new technology being developed at ETH Zurich is the magnetic steerable catheter, which could have some exciting applications in ophthalmology, said Mr Charreyon. Unlike a conventional catheter, which is steered manually, the magnetic version is operated from a computer via an external magnetic field. This enables the front part of the catheter to be bent in any direction with the highest level of precision. Eye surgery requires phenomenal dexterity where we are talking about precision needs that are measured in microns Samuel Charreyon MSc Courtesy of Samuel Charreyon MSc A magnetically-steered microcannula for performing subretinal injections