Robot-assisted vitreoretinal surgery: development of a prototype and feasibility studies in an animal model.

PURPOSE To develop a prototype robotic system designed to assist vitreoretinal surgery and to evaluate its accuracy and maneuverability. DESIGN Experimental study. PARTICIPANTS This study used harvested porcine eyes. METHODS After development of a prototype robotic system, pointing accuracy tests of the system were performed on graph paper and in harvested porcine eyes. The average maximal deviation from the aiming point to the actual position of the tip of the instrument was compared between manually conducted procedures and those conducted with robotic assistance. The feasibility of creating posterior vitreous detachment (PVD), retinal vessel sheathotomy (RVS), and retinal vessel microcannulation also were evaluated in porcine eye models, and the success rates of 4 consecutive attempts for each kind of procedure were evaluated. MAIN OUTCOME MEASURES The average maximum deviation in pointing accuracy tests both on graph paper and in animal eye models was a main outcome measure. The success rate of making PVD, RVS, and retinal vessel microcannulation was the other primary outcome measure. RESULTS The pointing accuracy was superior with robotic assistance both on graph paper (327.0 microm vs. 32.3 microm) and in animal eye models (140.8 microm vs. 33.5 microm). Creating PVD, RVS, and retinal vessel microcannulation was feasible in 4 of 4 attempts, 4 of 4 attempts, and 2 of 4 attempts, respectively. The 2 failures in microcannulation were considered to be the result of difficulty in visual differentiation between the retinal vessel and retina in harvested porcine eyes. CONCLUSIONS Improved accuracy and desirable feasibility of a prototype robotic system to assist vitreoretinal surgery were shown in this study. Research for wider implementation of robot-assisted surgery should be continued; there are some hurdles to overcome.