COMPARISON OF ATTRACTION CAPABILITIES ASSOCIATED WITH HIGH-SPEED, DUAL-PNEUMATIC VITRECTOMY PROBES

Abstract

In Brief Purpose: To measure membrane attraction capabilities of enhanced 27-gauge, enhanced 25-gauge, and 23-gauge vitrectomy probes under various parameters. Methods: A membrane-on-cantilever apparatus was used to measure membrane attraction for enhanced 27-, enhanced 25-, and 23-gauge UltraVit probes (n = 6 for each). The following parameters were evaluated: effects of cut rates and duty cycles on membrane attraction distances, and flow rates and vacuum levels required to attract a membrane at a fixed distance. Results: The enhanced 27-gauge probe had the shortest attraction distance across all cutting speeds and duty cycles. To attract a membrane at a fixed distance, increasing vacuum was necessary with higher cutting rates and smaller probe gauges but flow rate remained relatively constant. The biased open duty cycle was associated with a longer attraction distance than 50/50 or biased closed modes. Conclusion: The shorter membrane attraction distance of the enhanced 27-gauge probe versus 23-gauge and enhanced 25-gauge probes may permit greater membrane dissection precision while providing improved access to small tissue planes. Equivalent fluid flow capabilities of the 27-gauge probe compared with the 23-gauge and 25-gauge probes may provide efficient aspiration. Surgeon selection of duty cycle modes may improve intraoperative fluid control and expand the cutter utility as a multifunctional tool. This laboratory study investigated the effects of duty cycle, vacuum, and flow rate on membrane attraction of enhanced 27-gauge, enhanced 25-gauge, and 23-gauge vitrectomy probes. Larger probes and biased open duty cycle had a longer membrane attraction distance that was independent of cutting rates when operating at 50/50 duty cycle.