PURPOSE: To quantitatively evaluate hand tremors during retinal vascular cannulation surgery with a microneedle and investigate if a customized passive surgical robot suppresses hand tremors. METHODS: A surgical simulation eye was modified, and an analysis system was used that synchronized the surgical video and accelerometer attached to the tail of the microneedle syringe. A cannulation target mimicking the optic disc and retinal vessels was designed in the bottom of the artificial eye. Two vitreous surgeons used this system to evaluate hand tremor 15 seconds before cannulation and 60 seconds during cannulation with and without the robot. RESULTS: Fifteen seconds before cannulation, the mean horizontal, vertical, and combined components of hand tremor were 3.8 ± 1.7, 0.93 ± 0.48, and 4.0 ± 1.7 mG without the robot, decreasing to 3.3 ± 1.6, 0.87 ± 0.52, and 3.5 ± 1.8 mG with the robot. Significant reductions were observed in the horizontal (p = 0.012) and combined components (p = 0.020). Sixty seconds during cannulation, the mean horizontal, vertical, and combined components of hand tremor were 3.3 ± 1.0, 0.53 ± 0.24, and 3.4 ± 1.0 mG, respectively, without the robot. These components significantly decreased with the robot to 2.2 ± 0.7, 0.40 ± 0.15, and 2.2 ± 0.7 mG, respectively, for all components (p <
0.001). Hand tremor decreased significantly by 35% in the combined components during cannulation with the robot. CONCLUSION: The customized passive surgical support robot reduces hand tremor during simulated retinal vascular cannulation surgery.