Occlusion break surge performance of a next-generation phacoemulsification system.

PURPOSE: To compare occlusion break surge volumes of UNITY Vitreoretinal Cataract System (UVCS) with CENTURION Vision System with Active Sentry (CAS).

SETTING

Alcon Research, LLC., Lake Forest, California.

DESIGN

Experimental study.

METHODS

An eye model representing average human eye compliance was used to determine average occlusion break surge volumes. UVCS was tested at target intraocular pressures (IOPs) of 20 mm Hg, 30 mm Hg, 40 mm Hg, 50 mm Hg, 60 mm Hg, and 80 mm Hg; vacuum limits of 300 mm Hg, 400 mm Hg, 500 mm Hg, 600 mm Hg, and 650 mm Hg; and aspiration flow rates of 20 cc/min and 40 cc/min. CAS was tested at target IOPs of 30 mm Hg, 40 mm Hg, 50 mm Hg, 60 mm Hg, and 80 mm Hg, and at the same set vacuum limits and aspiration flow rates as UVCS. In addition, a second-order polynomial was fit to the entire dataset to compare UVCS and CAS at a target IOP of 20 mm Hg.

RESULTS

After calculating sample means at each setpoint combination, the largest mean surge volume was 48 μL for UVCS and 75 μL for CAS, corresponding to 19% and 30%, respectively, of the average human phakic anterior chamber volume. For all common setpoint combinations, mean occlusion break surge volumes were 44% lower for UVCS than CAS. At a flow rate of 40 cc/min and IOP setpoint of 20 mm Hg, UVCS showed a 46% average decrease across all vacuum limits.

CONCLUSIONS

UVCS demonstrated lower mean surge volumes after occlusion break than CAS. This may give surgeons greater confidence operating at lower IOPs and may reduce the risk of posterior capsule rupture, especially in complex cases.