Low Intraocular Pressure Fluidic Setting Enhances The Safety Of Phacoemulsification Reflected Through Active Surge Mitigation Actuation

To evaluate the influence of demographic and biometric factors, lens hardness, conditions such as Pseudoexfoliation Syndrome (PEX) and Intraoperative Floppy Iris Syndrome (IFIS), and intraoperative metrics on Active Surge Mitigation (ASM) actuation during phacoemulsification at low intraocular pressure (IOP) settings using the Centurion® Vision System ACTIVE SENTRY® Handpiece.

University Eye Clinic, University Hospital "Sveti Duh," Zagreb, Croatia.

Preoperative analysis included age, gender, biometric data (measured with the Zeiss IOL Master 700), and lens hardness classified by the Lens Opacification Classification System (LOCS III). The presence of IFIS and PEX was also considered. Intraoperative parameters recorded during phacoemulsification included total case time, cumulative dissipated energy (CDE), total ultrasound time (U/S time), and the number of active surge mitigation (ASM) actuations. All surgeries were performed by a single skilled surgeon (BKE) using the ACTIVE SENTRY ® Handpiece with a low fluidic setting: infusion pressure of 30 mmHg, bottle height of 41 cm, vacuum of 575 mmHg, and aspiration flow rate of 28 cc/min.

ASM actuation values during phacoemulsification at low IOP settings were not normally distributed (median=1; mean=2.4). Significant positive correlations were observed with age (P=0.014), lens thickness (P=0.039), and ultrasound time (0.015), while no significant differences in ASM actuation numbers were found for ACD, gender, PEX, or IFIS. A binary logistic regression model identified age as a key predictor of ASM values ≥1. 

Surge events are less likely during phacoemulsification, at low IOP settings. ASM actuations increase with patient age, lens thickness and longer ultrasound time. Anterior chamber depth remains stable, showing no significant correlation with ASM actuations at low IOP setting. No significant differences were observed in ASM actuation number between genders or in patients with PEX or IFIS.