Enhancing Phacoemulsification Safety: How Low Fluidic Settings Influence Active Surge Mitigation Actuation.

Introduction: Active Surge Mitigation (ASM) is a feature of the Centurion Vision System ACTIVE SENTRY^® Handpiece designed to minimize post-occlusion surge by dynamically adjusting fluidics. Stable anterior chamber conditions are critical during phacoemulsification, and low intraocular pressure (IOP) fluidics may enhance surgical safety by reducing stress on ocular tissues. This study evaluated demographic, biometric, and intraoperative factors influencing ASM activation during phacoemulsification at low IOP settings (30 mmHg), a vacuum of 575 mmHg, and an aspiration flow of 28 cc/min.

Methods: This retrospective study was conducted at the University Eye Clinic, University Hospital "Sveti Duh" in Zagreb, Croatia, between January 19 and April 12, 2024. Preoperative parameters included age, gender, biometric data from the Zeiss IOL Master 700, and lens hardness, classified according to the Lens Opacities Classification System (LOCS III). The presence of Pseudoexfoliation Syndrome (PEX) and Intraoperative Floppy Iris Syndrome (IFIS) was noted. Intraoperative metrics recorded were total case time, cumulative dissipated energy (CDE), ultrasound time (U/S time), and the number of ASM actuations.

Results: ASM actuations were not normally distributed (median = 1; mean = 2.4). Significant positive correlations were identified with age (P = 0.014), lens thickness (P = 0.039), and U/S time (P = 0.015), while no significant differences were observed for anterior chamber depth (ACD), gender, PEX, or IFIS. Logistic regression identified age as a predictor of ASM values ≥1.

Conclusion: At low IOP settings, surge events during phacoemulsification are rare. ASM activation is influenced by patient age, lens thickness, and U/S time but not by ACD, gender, PEX, or IFIS. Low IOP fluidics combined with ASM contributes to stable and safe chamber dynamics across diverse patient profiles.