Ocular perfusion pressure control during pars plana vitrectomy: testing a novel device.

Abstract

To study the efficacy of a novel device intended to control infusion pressure based on mean ocular perfusion pressure (MOPP) during pars plana vitrectomy (PPV). An arm blood pressure cuff connected to a vitrectomy machine calculated mean arterial pressure (MAP), while a pressure sensor close to the infusion trocar measured intraocular pressure (IOP). MOPP was calculated in real time in 36 consecutive patients undergoing PPV, who were divided into two groups. The device lowered IOP every time that calculated MOPP fell below 30mmHg in the Control ON group (18 patients), while no action was taken in the Control OFF group (18 patients). Baseline IOP and blood pressure were similar between groups. The Control ON group had significantly lower average intraoperative IOP (30.5±2.1 vs. 35.9±6.9mmHg; p=0.002) and higher MOPP (56.4±5.9 vs. 49.7±6.1mmHg) than the Control OFF group. The Control ON group also spent less time at MOPP <10mmHg and <30mmHg: 0 vs. 3.40±2.38min (p<0.001) and 9.91±7.15 vs. 16.13±8.12min (p=0.02), respectively. The MOPP control device effectively maintained lower IOP and higher MOPP throughout surgery. It also helped avoid dangerous IOP peaks and MOPP dips, allowing patients to spend less time at MOPP of <10 and <30mmHg.