Phacoemulsifier occlusion break surge volume reduction.

Purpose: To compare the volumetric occlusion break surge responses of phacoemulsification units from 1 company over 3 generations under varying vacuum limits and target intraocular pressure (IOP) settings.

Setting: Alcon Research, Ltd., Lake Forest, California, USA.

Design: Experimental study.

Methods: Three generations of phacoemulsification units (Infiniti Vision System, Centurion Vision System, and Centurion Vision System with Active Sentry upgrades) were tested. Volumetric surge responses were measured after occlusion breaks at vacuum limits of 200 mm Hg, 300 mm Hg, 400 mm Hg, 500 mm Hg, and 600 mm Hg and target IOPs of 30 mm Hg, 55 mm Hg, and 80 mm Hg. An acrylic test chamber with a piston attached to 3 springs modeled the human eye in this study. The springs were calibrated to mimic volumetric changes in the eye over a wide range of IOPs.

Results: Occlusion break surge volumes varied from 17.4 μL to 153 μL, corresponding to 7% and 61%, respectively, of the aqueous volume in the average phakic eye and to 4% and 33% of the aqueous volume in the average aphakic eye.

Conclusion: Occlusion break surge volumes decreased with increasing target IOP, decreasing vacuum limit, and each generational increment in the phacoemulsification system.