Abstract
Purpose :
As a source of chamber instability during cataract surgery, post-occlusion surge (POS) is related to the compliance of the aspiration tubing. New fluidics packs with a small-bore, dual-durometer aspiration tubing were constructed. This study was to evaluate the performance of these fluidics packs with a new phacoemulsification machine on POS in a laboratory benchtop setting.
Methods :
The inner layer of the aspiration tubing of the new fluidics packs uses a stiffer material with a smaller inner diameter than existing products, while the outer layer is soft to maintain flexibility. These packs were tested in a newly developed phacoemulsification console in peristaltic mode, along with existing packs as the control arm. A rigid body, leak-tight fixture with small internal volume and an attached pressure sensor were used to simulate the anterior chamber. A phacoemulsification handpiece with a 20G straight tip and sleeve was inserted tightly into the fixture and connected to a fluidics pack. The occlusion mechanism was created with a solenoid valve. A bottle height to generate a static irrigation pressure of 65 mmHg, an aspiration flow rate of 30 cc/min, and five vacuum presets of 200, 300, 400, 500, and 600 mmHg, were selected for this study. The intraocular pressure (IOP) waveforms were measured and recorded continuously during occlusion and occlusion break.
Results :
At the vacuum preset of 400 mmHg, the new fluidics packs performed 20% better in terms of the IOP change, from the static value during occlusion to the trough of the IOP curve post occlusion, than the existing fluidics packs. For the vacuum presets from 300 to 600 mmHg, the new packs performed at least 35% better in surge area, the calculated area between the +20mmHg line and the IOP curve below this line, than the existing packs. The surge area was essentially zero at 200 mmHg vacuum for both types of fluidics packs.
Conclusions :
This study demonstrated that the new fluidics pack with small-bore, dual-durometer aspiration tubing performed much better than the existing fluidics pack in post-occlusion surge in a new phacoemulsification machine in terms of the IOP change and the surge area in a laboratory setup, providing improved chamber stability.
This is a 2021 ARVO Annual Meeting abstract.