New robotic surgery device aims to improve precision in retinal procedures

New robotic surgery device aims to improve precision in retinal procedures

When even the most trained surgeons perform procedures on the retina—one of the smallest and most sensitive parts of the human body—the stakes are high. Surgeons must account for patients' breathing, snoring and eye movements, as well as their own involuntary hand tremors, while working on a layer of cells less than a millimeter thick.

That's why researchers at the University of Utah's John A. Moran Eye Center and the John and Marcia Price College of Engineering collaborated to create a new robotic surgery device designed to give surgeons "superhuman" hands.

The robot itself is extremely precise, making movements as small as 1 micrometer (smaller than a single human cell). It is mounted directly to the patient's head with a helmet so that subtle (and sometimes not so subtle) movements of the patient's head are compensated for, keeping the eye fairly still from the robot's perspective. The robot also scales the surgeon's movements, measured with a handheld robotic device known as a haptic interface, at the much smaller surgical site within the eye, compensating for handlemors along the way.

While the device is still in testing, it is expected to improve patient outcomes and support cutting-edge procedures, including the delivery of gene therapies for inherited retinal diseases.

The researchers successfully tested the robot with enucleated pig eyes and published their results in the journal this weekScience Robotics.The study was led by Jake Abbott, a professor in the U's Department of Mechanical Engineering, and Moran Eye Center retinal specialist Paul S. Bernstein.

The retina contains the light-sensitive rod and cone cells, which form the basis of vision. Several inherited disorders cause these cells to form incorrectly, resulting in vision problems of varying severity, but new gene therapy techniques could reverse these conditions.

Treatments for vision problems are advancing rapidly. We need to give surgeons a better ability to keep up with them. “

Jake Abbott, Professor, Department of Mechanical Engineering, University of Utah

For example, the first gene therapy approved by the U.S. Food and Drug Administration for an inherited retinal disease requires an injection into the space between the retina and another layer of cells known as the retinal pigment epithelium. In addition to the complications presented by eye movements and hand tremors, this subretinal target is infinitesimally small. The surgeon must introduce the drug between two submillimeter-thin layers of cells.

Since the device is not yet approved for operation on human subjects, a human volunteer had to be equipped with special glasses that allowed an animal eye to be mounted directly in front of their natural eye. This allowed the researchers to test the robot's ability to compensate for head movements and correct handlebars while operating on animal tissue, without risk to the volunteer.

In the experiments described in the study, surgeons achieved higher success rates using the robotic surgical device to perform subretinal injections while avoiding ophthalmic complications.

These results show that the robot has improved patient care, according to co-author Eileen Hwang, a retinal surgeon at Moran Eye Center.

“This robot's unique feature, head attachment, can allow patients to have subretinal injections under intravenous (IV) sedation rather than general anesthesia,” Hwang said. "IV sedation allows for faster recovery and is safer for some patients. Robots can also enable more precise delivery of gene therapy drugs compared to manual injections for more reproducible and safer treatments."

As the robot makes its journey from the lab to the operating room, its journey is strengthened by the kind of interdisciplinary collaborations that first brought it to life.

“These collaborations are wonderful at the University of Utah,” Bernstein said. “When I have ideas, the engineers, the chemists, the physics are just a few blocks away.”

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