Abstract
Purpose :
As IOP maintenance during vitrectomy surgery is a critical parameter, this study aims to 1) understand the IOP performance of 27+® Gauge (Ga) dual-cutting, 20K cuts per minute (cpm) beveled vitrectomy probes under different system settings, and 2) help surgeons to optimize their system settings during surgery.
Methods :
27+® HYPERVIT® beveled 20K cpm vitrectomy probes were driven by a CONSTELLATION® Vision System (Alcon Vision, LLC.) to aspirate sterile irrigating solution (BSS®) in a hollow acrylic eye model. A digital transducer (OMEGA, PX409-001GUSBH) was connected to the bottom of eye model to detect IOP change during aspiration. Six samples were tested under core duty cycle and vacuums of 250mmHg, 450mmHg and 650mmHg. Cut rate ranged from 2500cpm to 20,000cpm. Both system IOP compensation enabled and disabled were used. Average IOP during aspiration was calculated for each test setting and statistical analyses were performed using Kruskal-Wallis test with statistical significance level of p<0.05.
Results :
At 450mmHg, without IOP compensation, the IOP ranged from 15.46 ± 0.33 to 15.62 ± 0.33 mmHg when the cut rate changed from 2500cpm to maximum cut rate of 20,000cpm. When IOP compensation was enabled, IOP ranged from 28.21± 1.74 to 28.43 ± 1.71 mmHg for cut rate from 2500cpm to 20,000cpm. Statistical analysis indicated that there was no significant difference between results using various cut rate for both IOP compensation enabled and disabled (p>0.05). At the maximum cut rate and without IOP compensation, IOP was 22.81 ± 0.37 mmHg under 250mmHg, 15.62 ± 0.33 mmHg under 450mmHg and 8.33 ± 0.32mmHg under 650mmHg. Corresponding average flow rate was 3.23 ± 0.1 cc/min under 250mmHg, 5.57 ± 0.17 cc/min under 450mmHg and 7.46 ± 0.27 cc/min under 650mmHg. When IOP compensation was enabled, IOP at maximum cut rate significantly increased to 29.24 ± 0.75 mmHg (28% improvement) for 250mmHg, 28.43 ± 1.71 mmHg(82% improvement) for 450mmHg and 27.42± 2.64 mmHg (229% improvement) for 650mmHg compared with result without system’s intervention(p<0.05).
Conclusions :
27+® Ga Dual-Cutting 20Kcpm vitrectomy probes have constant IOP performance under different cut rates. IOP ranges during aspiration are improved with IOP compensation enabled. Using 27+® Ga 20K cpm vitrectomy probe and IOP compensation can help surgeons use different operation settings to attain a controllable and efficient process.
This is a 2021 ARVO Annual Meeting abstract.