A Translational Vision Science & Technology by Rossi et al. has systematically compared the efficiency of different commercial fluid infusion systems used in pars plana vitrectomy (PPV). The study aimed to quantify how various designs affect intraocular pressure (IOP) stability during aspiration.
Using a controlled experimental setup mimicking the human vitreous chamber, the researchers tested 23G, 25G, and 27G infusion sets from five major manufacturers: Alcon, Bausch & Lomb, BVI, DORC, and Optikon. Measurements focused on the pressure drop across the infusion system during flow rates ranging from 0 to 10 mL/min. They found that the pressure drop increased as the gauge decreased and varied significantly among brands.
The results showed that DORC and BVI systems consistently exhibited the lowest pressure drops, regardless of gauge, due to their innovative design that eliminates the traditional metal infusion cannula and avoids lumen narrowing. In contrast, other systems showed greater pressure loss, particularly at smaller gauges (e.g. 27G), which could result in IOP fluctuations during aspiration.
The study further analyzed the pressure loss components: linear losses due to tubing friction and quadratic losses caused by abrupt lumen changes at the outlet. At smaller gauges, linear friction from narrow cannula lumens became the dominant factor in overall head loss. This finding highlights the importance of minimizing resistance at the infusion cannula–trocar interface, especially during high-flow phases like vitreous base shaving.
Clinically, these findings underscore that the design of infusion sets directly impacts ocular pressure stability. While modern vitrectomy consoles often use active infusion compensation systems, starting with a more efficient infusion set reduces the burden on these mechanisms and may improve patient safety.
