Performance analysis of new-generation vitreous cutters

Background Despite their clinical advantages, smaller-diameter vitrectomy systems pose significant challenges in vitreous removal. The percentage of time the vitreous cutter port is open while cutting (duty cycle) is one of the primary factors that affect flow. Herein, we examine the effect of duty cycle on the flow performance of new-generation cutters relative to current instrumentation. Methods Performance of 25-gauge (ga) and 20-ga new-generation spring-return pneumatic cutters ( n = 24 and n = 28 respectively) was analyzed relative to current-generation cutters, across their specified cut-speed range under clinical vacuum pressures of 500 mmHg (25-ga) and 200 mmHg (20-ga). A precision balance measured mass of water or porcine vitreous removed from a vial by a cutter; this was recorded in real-time and converted to flow rates. Frame-by-frame analysis of high-speed video was used to determine duty cycle. Data was analyzed using linear regression and the t -test. Results Compared with the current-generation, the new-generation cutters exhibit increasingly greater water flow rates at higher cut speeds ( P