For the First Time, Surgical Eye Robot Performs Precision Injection in Patient with Retinal Vein Occlusion

Source: University Hospitals Leuven

Surgeons at the University Hospitals Leuven in Belgium were the first to operate using a surgical robot on a patient with retinal vein occlusion (RVO). Operated by an eye surgeon, the robot uses a needle of barely 0.03 mm to inject a thrombolytic drug into the retinal vein of the patient. The KU Leuven team developed the robot and needle specifically for this procedure. The operation was successful and for the first time, the procedure shows it is technically possible to safely dissolve a blood clot from the retinal vein with robotic support. A phase 2 trial now has to show what the clinical effect is for patients with retinal vein occlusion, a disorder that can lead to blindness.

In cases of RVO, there is a blood clot in one of the retinal veins. This leads to reduced eyesight or even blindness in the affected eye. Treatment consists of monthly injections in the eye that only reduces the side effects of the thrombosis. Until recently, taking away the blood clot itself was not possible.

Researchers from the University Hospitals Leuven and the KU Leuven are studying retinal vein cannulation (RVC), a revolutionary treatment that addresses the cause of retinal vein occlusion by removing the blood clot in the retinal vein. RVC is a promising method requiring the eye surgeon to insert an ultrathin needle into the vein and inject ocriplasmin that can dissolve the blood clot. This requires extreme precision as a retinal vein only has the width of a tenth of a millimeter, about the same width as a human hair. No surgeon can manually inject a drug into such a thin vein while holding the needle perfectly still for 10 minutes; the danger of damaging the vein or the retina is too high.

This is why researchers from the department of mechanical engineering of the KU Leuven developed a robotic device enabling the surgeon to insert the needle into these veins in a precise and stable way, after which the robot can hold the needle perfectly immobile. In contrast to most surgical robots, there is no need for a joystick to operate the device. The eye surgeon and the robot comanipulate the instrument. The surgeon guides the needle into the vein while the robot eliminates any vibration of the needle, hereby increasing the level of precision more than tenfold. After locking the robot, the needle and the eye are automatically stabilized. The surgeon can then inject the ocriplasmin into the vein in a controlled way. The researchers also had to develop the ultrathin injection needle: the needle point has a width of barely 0.03 millimeters, 3 times thinner than a human hair.

The robot is the result of 7 years of research and cooperation between KU Leuven engineers and University Hospitals Leuven ophthalmologists. The current phase 1 trial aims to demonstrate that it is technically feasible to use a robotic device to insert a microneedle into the retinal vein and to inject ocriplasmin to dissolve the blood clot. On January 12, 2017, the procedure was performed for the first time on a University Hospitals Leuven patient. The patient is doing well and will start working on the rehabilitation of the eye. In a subsequent phase 2 trial, the physicians will study the clinical effects of the procedure.

“Current treatment for retinal vein occlusion costs €32,000 per eye, a high price tag, especially if you know that you are only treating the side effects and that there is little more you can do than avoid decreasing eye sight," Prof. Peter Stalmans, MD, an eye surgeon at the University Hospitals Leuven, said in a company news release. "The robotic device enables us to treat the cause of the thrombosis in the retina for the first time. I am, therefore, looking forward to what is next. If we succeed, we will literally be able to make blind people see again.”

“We are proud that our robot enables us to perform eye surgery that was previously impossible to perform safely. This brings us one step closer to commercializing this ground-breaking technology. We look forward to making other revolutionary procedures possible with this robotic device and to improving the quality of existing surgical treatments," Prof. dr. ir. Dominiek Reynaerts from the KU Leuven Department of Mechanical Engineering, said in the news release.


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