Oxford researchers have completed the first clinical trial of a robotic system for retinal surgery. The remote-controlled PRECEYES Surgical System safely dissected retinal tissue with “supra-human precision,” the investigators reported June 18 in Nature Biomedical Engineering.
“This is a huge leap forward for delicate and technically difficult surgery,” said lead investigator Robert MacLaren, MD, a surgeon and professor of ophthalmology at the University of Oxford. “A safe and viable robotic system for intraocular surgery would enable precise and minimally traumatic delivery of gene therapy or cell therapy to the retina.”
The team presented preliminary findings from the trial’s 12 participants last year at the Association for Research in Vision and Ophthalmology annual meeting. The final outcomes are described in the new paper.
Six patients received robot-assisted surgery and 6 underwent standard manual dissection of the epiretinal or inner limiting membrane over the macula. The robot also guided a fine needle under the retina and injected recombinant tissue plasminogen activator to displace sight-threatening hemorrhages in an additional 3 patients with AMD.
Robotic surgery has long been criticized for enhancing precision at the cost of prolonged surgical times. The PRECEYES system doesn’t overcome this challenge—dissection took nearly 5 minutes with robotic surgery versus about 1.5 minutes with manual surgery—but investigators say the system offers other features that may give it an edge over previous attempts at robotic surgery.
Surgeons use a joystick to maneuver a robotic arm, which pivots around the scleral entry site and steers the instrument into position inside the eye. This design enhances intraocular stability, minimizes tractional forces on the globe and prevents instrument deflection due to friction or eye movements. The system features 7 independent computer-operated motors to expand the range of motion and dynamic motion scaling to adjust the instrument’s position inside the eye.
Despite the robot’s accuracy and stability, the groups had similar outcomes and rates of retinal microtrauma. The median number of iatrogenic retinal touches or microhemorrhages was 1 in the manual group and 0 in the robot group, but the study was not large enough to show statistical significance. Still, scientists expect the device’s true advantages to come to light as new gene therapies hit the market.
“Our next step will be to use the robotic surgical device for precise and minimally traumatic delivery of a gene therapy to the retina, which will be another first-in-man achievement and is set to commence in early 2019,” MacLaren said.