Retinal Vein Occlusion (RVO) is a blinding disease caused by one or more occluded retinal veins. Current treatment methods only focus on symptom mitigation rather than targeting a solution for the root cause of the disorder. Retinal vein cannulation is an experimental eye surgical procedure which could potentially cure RVO. Its goal is to dissolve the occlusion by injecting an anticoagulant directly into the blocked vein. Given the scale and the fragility of retinal veins on one end and surgeons' limited positioning precision on the other, performing this procedure manually is considered to be too risky. The authors have been developing robotic devices and instruments to assist surgeons in performing this therapy in a safe and successful manner. This work reports on the clinical translation of the technology, resulting in the world-first in-human robot-assisted retinal vein cannulation. Four RVO patients have been treated with the technology in the context of a phase I clinical trial. The results show that it is technically feasible to safely inject an anticoagulant into a [Formula: see text]-thick retinal vein of an RVO patient for a period of 10 min with the aid of the presented robotic technology and instrumentation.

PurposeTo evaluate the feasibility of robot assisted retinal vein cannulation for retinal vein occlusion.MethodsProspective experimental study performed in in vivo porcine eyes. A standard three port pars plana vitrectomy was followed by laser induced branch retinal vein occlusion. Consequently, a retinal vein cannulation with the help of a surgical robot and a micro‐needle was performed. Complete success was defined as a stable intravenous position of the needle tip confirmed by blood washout for at least 3 min. Secondary outcomes were the occurrence of intraoperative complications and technical failures.ResultsCannulation was successful in 15 out of 18 eyes with a complete success rate (duration of infusion of more than 3 min) of 73.3% after exclusion of 2 eyes from analysis due to failure in establishing a blood clot. There were no technical failures regarding the robotic device. The intravessel injections of ocriplasmin in 2 out of 2 eyes led to a clot dissolution. In a subset of 5 eyes, a second cannulation attempt at the border of the optic disc resulted in a stable intravessel position and infusion during 361.8 (±138.5) seconds.ConclusionsRobot assisted retinal vein cannulation with prolonged infusion time is technically feasible. Human experiments are required to analyze the clinical benefit of this new therapy.

Retinal Vein Occlusion is a common retinal vascular disorder which can cause severe loss of vision. Retinal vein cannulation followed by injection of an anti-coagulant into the affected vein is a promising treatment. However, given the scale and fragility of the surgical workfield, this procedure is considered too high-risk to perform manually. A first successful robot-assisted procedure has been demonstrated. Even though successful, the procedure remains extremely challenging. This paper aims at providing a solution for the limited perception of instrument-tissue interaction forces as well as depth estimation during retinal vein cannulation. The development of a novel combined force and distance sensing cannulation needle relying on Fiber Bragg grating (FBG) and Optical Coherence Tomography (OCT) A-scan technology is reported. The design, the manufacturing process, the calibration method, and the experimental characterization of the produced sensor are discussed. The functionality of the combined sensing modalities and the real-time distance estimation algorithm are validated respectively on in-vitro and ex-vivo models.

The results demonstrate the feasibility of deploying a combined sensing instrument in an in vivo setting. The performed study provides a foundation for further work on real-time local modelling of the surgical scene. This paper provides initial insights; however, additional processing remains necessary.

The developed bio-impedance sensor has shown great promise to help in avoiding double punctures when cannulating retinal veins. Compared to other puncture detection methods, the proposed sensor is simple and therefore potentially more affordable. Future research will include validation in an in vivo situation involving vitreoretinal surgeons.

The use of McKibben pneumatic artificial muscles in surgical instruments is increasing due to their light weight, miniaturization potential, compliance and large actuation force. However, precise position and force control is still challenging due to the intrinsic muscle hysteresis. The present work proposes an easy-to-make integrated capacitance sensor for miniature artificial muscles by replacing two strands of the muscle braid with two conductive wires. By measuring the capacitance at high excitation frequency between both wires, the length of the muscle can be deduced. This new integrated sensor still allows the miniaturization of McKibben muscles. The miniature muscle with integrated capacitance sensing only loses 3% of its contraction length with regard to an original McKibben muscle. The sensor can predict the muscle length with a 0.31mm precision over 80% of the muscle total achievable contraction range in average.

Robot-assisted retinal vein cannulation with prolonged infusion time is technically feasible. Human experiments are required to analyse the clinical benefit of this new therapy.

Purpose To evaluate the safety and feasibility of robot‐assisted retinal vein cannulation with Ocriplasmin infusion for central retinal vein occlusion. Methods Prospective phase I trial including four patients suffering from central retinal vein occlusion (CRVO). Diagnosis was confirmed by preoperative fluo‐angiography and followed by a standard three‐port pars plana vitrectomy. Afterwards, a custom‐built microneedle was inserted into a branch retinal vein with robotic assistance and infusion of Ocriplasmin started. Primary outcomes were the occurrence of intra‐operative complications and success of cannulation. Secondary outcomes were change in visual acuity, central macular thickness (CMT) and venous filling times (VFT) during fluo‐angiography two weeks after the intervention. Results Cannulation with infusion of ocriplasmin was successful in all four eyes with a mean total infusion time of 355 ± 204 seconds (range 120–600 seconds). Best corrected visual acuity (BCVA) remained counting fingers (CF) in case 3 and 4, increased in case 1 from CF to 0.9LogMAR and decreased in case 2 from 0.4 to 1.3 LogMAR. CMT and VFT both showed a trend towards significant decrease comparing preoperative measurements with two weeks postintervention (1061 ± 541 μm versus 477 ± 376 μm, p = 0.068) and 24 ll 4 seconds versus 15 ± 1 seconds, p = 0.068, respectively). In one eye a needle tip broke and could be removed with an endoforceps. There were no other intervention‐related complications. Conclusion Robot‐assisted retinal vein cannulation is feasible and safe. Local intravenous infusion with Ocriplasmin led to an improved retinal circulation.