Abstract
Purpose :
IOP stability during vitrectomies with dual action cutters can be achieved using inflow outflow compensation factors. We aim to explain the new IOP system options with dual action cutters and to inform surgeons on how this may optimize and streamline surgeries.
Methods :
Clinical: Surgical case data with infusion pressure, vitrectomy time, and vacuum level from 465 surgeries without PAF were downloaded from the Eyetelligence® cloud. These were compared to 30 surgeries case summary data during a clinical study with PAF enabled. All the surgeries were executed by a single surgeon with the 25g, 15 kcpm bi-blade® dual action cutter.
Benchtop: 25g bi-blade® and standard single port vitrectomy probes were driven by the Stellaris Elite Image enhancements system (Bausch & Lomb, LLC), aspirating BSS in a silicone test chamber from 0 to 25,000 cpm. A pressure transducer (Fluke DPM2Plus) connected to oscilloscope (Tektronix DPO3014) measured IOP. 5 tests per vacuum were measured at: 100, 200, 400, 660 mmHg with and without PAF. Infusion and aspiration rates were measured using scales after 1 minute in an open vessel.
Results :
Clinical: PAF enabled surgeries showed 62% reduction in average infusion pressure during PAF enabled surgeries at 21.7±8.9 PAF and 56.5±6.9 mmHg non-PAF (p<0.001) , with similar vitrectomy times 4:15±2:54 and 4:12±2:29 min:sec (p>0.4), and similar vacuum levels 473±123.1 and 507±90 mmHg (p>0.05), respectively.
Benchtop: 25g Bi-Blade BSS flow rates were insensitive to cut rate and provided constant high aspiration flows of 15.3 +-0.8 ml/min compared to a single action cutter from 15.4 ml/min at 0 cpm down to 6 ml/min at 7.5 kcpm. Infusion rates correlated to infusion pressures and 15 ml/min was achieved at 33 mmHg. Test chamber IOP results show significant improvement with PAF and maintained a range closer to physiological IOP (10 – 20 mmHg) with average improvements over no-PAF of: 4.2 mmHg at 200 mmHg vacuum, 11.8. mmHg at 400 mmHg vacuum, and 24 mmHg at 660 mmHg vacuum (all with p<0.01).
Conclusions :
Posterior Adaptive Fluidics significantly increases IOP performance during vitrectomies and can maintain IOP at any given cut rate (0 to 25,000 cpm). The dual action 25g cutters with PAF can increase usability and de-necessitates infusion pressure change during vitrectomies.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.