Medical robots like Intuitive Surgical's da Vinci line have been lending a hand in the operating theater for years, opening up a range of procedures that were previously impossible. Now, for the first time, surgeons at the University of Oxford have used a remote-controlled robot to perform a delicate operation inside the eye with sub-millimeter precision not normally afforded by the human hand.

Keyhole surgery techniques are making procedures less invasive for patients, reducing recovery times and the risk of infection. Needle-thin instruments can enter the body through small incisions or orifices like the ear and allow finely-tuned operations beyond the scope of human ability, like operating on a heart while matching the rhythm of its beating, removing the need to stop the heart completely.

For the Oxford procedure, a membrane measuring around a 100th of a millimeter thick on the surface of the patient's retina had contracted, which was distorting his vision. Removing this membrane from the retina would be an incredibly delicate operation, and though it may be possible for human surgeons to perform, doing so would require them to actually slow their own pulse and time their hand movements around their heart beats.

That's where the Robotic Retinal Dissection Device (R2D2) comes in. Seven motors able to be controlled independently by a computer allow its movements to be as tiny as a 1,000th of a millimeter, which is well within the scale of the offending membrane. The device entered the patient's eye through a hole less than 1 mm (0.04 in) wide, and throughout the operation needed to keep locating this hole even as the eye itself may move around.

Professor Robert MacLaren controlled the robot from the operating theater using a joystick and touchscreen that translated his normal-scale movements down to the sub-millimeter scale of the robot. MacLaren could watch what was happening through an operating microscope. In the end, the operation was a success, with the patient's sight beginning to return.

"There is no doubt in my mind that we have just witnessed a vision of eye surgery in the future," says MacLaren. "Current technology with laser scanners and microscopes allows us to monitor retinal diseases at the microscopic level, but the things we see are beyond the physiological limit of what the human hand can operate on. With a robotic system, we open up a whole new chapter of eye operations that currently cannot be performed."

This promising procedure was part of the first stage of a trial, which will involve a total of 12 patients. In the second phase, the robot will be tasked with injecting fluid through a needle placed under the retina, which may ultimately lead to new gene therapy techniques to help treat blindness.

'This will help to develop novel surgical treatments for blindness, such as gene therapy and stem cells, which need to be inserted under the retina with a high degree of precision," says MacLaren.