RESUMO
PURPOSE: To construct a quantitative evaluation system for hand tremor during internal limiting membrane (ILM) peeling and investigate changes in hand tremor attributable to the use of the customized passive surgical support robot. METHODS: This analytical and experimental study developed a hand tremor evaluation system that synchronizes three elements: surgical microscope images, an artificial eye module with a force sensor to simulate ILM peeling, and microforceps with an inertial measurement unit. Two surgeons used this system to measure hand tremor during ILM peeling with and without the robot. RESULTS: The horizontal, vertical, and combined vertical and horizontal components of hand tremor were 8.1 ± 6.1, 1.7 ± 1.8, and 8.5 ± 6.2 mG, respectively, in the no robot group. These components decreased to 7.2 ± 6.0, 1.5 ± 1.7, and 7.5 ± 6.1 mG, respectively, in the robot group. In particular, hand tremor was significantly suppressed by 11.9% for the horizontal component using the robot (p = 0.0006). CONCLUSION: The newly constructed system helps to quantitatively evaluate hand tremor during ILM peeling. The customized passive surgical support robot enables to decrease hand tremor during ILM peeling.
RESUMO
This study aimed to develop a quantitative analysis program of blood flow velocity by vessel diameter in neovascular age-related macular degeneration (nAMD) subjects using high-speed swept-source optical coherence tomography angiography. This retrospective, observational, cross-sectional study included 10 eyes of healthy volunteers and 4 eyes of patients with representative nAMD. Novel scan patterns and variable interscan time analysis were utilized to measure the flow parameter, a surrogate marker of blood flow velocity, by vessel diameter within different depths. Detected vessels at superficial and deep as well as outer retinal regions were categorized into three vessel diameters (major vessels (> 40 µm), medium vessels (20-40 µm), and capillaries (< 20 µm)). The flow parameter increased with enlarged vessel diameter in all participants at superficial and deep layer. All nAMD subjects, except for type 3 macular neovascularization (MNV), contained a structure dominated by medium vessels at outer retinal region. The mean flow parameter at outer retinal region was type 1 MNV (1.46 ms-1), type 1 + 2 MNV (0.98 ms-1), and polypoidal choroidal vasculopathy, including branching vascular networks (1.46 ms-1). This program provides the possibility to extract the blood flow information at different depths by vessel diameter types, which is considered to be useful tool for evaluating nAMD pathology and activity.