Early changes in retinal microcirculation after uncomplicated cataract surgery using an active-fluidics system

Application of the Active-Fluidics System in Phacoemulsification: A Review

The fluidics system is an indispensable and primary component of phacoemulsification. Both the gravity-fluidics system and active-fluidics system are commonly used in practice. The irrigation pressure of the gravity-fluidics system is determined by the bottle height, which is relatively constant, while the active-fluidics system is paired with a cassette that contains pressure sensors to monitor intraocular pressure changes. The active-fluidics system allows surgeons to preset a target intraocular pressure value, and it replenishes the fluids proactively; thus, the intraocular pressure is consistently maintained near the target value. Under such circumstances, stable intraocular pressure and anterior chamber volume values could be acquired. Research on surgical safety, efficiency and results have reported several strengths of the active-fluidics system. It is also advantageous in some complicated cataract surgeries. However, the system is not widely used at present, mainly due to its low penetration rate and high equipment cost. Some of its updates such as the new Active Sentry handpiece showed potential superiority in laboratory studies recently, but there is still further research to be conducted. This article gives an overview of the mechanism and performance of the active-fluidics system, and it is expected to provide clues for future research.

Active-fluidics versus gravity-fluidics in lens extraction: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To investigate differences in outcomes between active-fluidics and gravity-fluidics phacoemulsification systems.

METHODS

We searched PubMed, Embase, and Cochrane Library databases for randomized controlled trials (RCTs) published no later than December 1, 2021. The Cochrane Collaboration risk of bias tool was used for quality assessment. We presented the outcomes as standardized mean differences (SMDs) with 95% confidence intervals (CI). Sensitivity analysis was performed by removing studies that included ≥2 types of phacoemulsification tips.

RESULTS

We analyzed six RCTs that totally enrolled 884 patients. Patients undergoing lens extraction with active-fluidics systems exhibited lower cumulative dissipated energy (CDE), total aspiration time (TAT), and estimated fluid usage (EFU) compared with patients who did not (SMD [95% CI]: CDE, - 0.818 [ - 1.054 to - 0.582]; TAT, - 0.664 [ - 0.850 to - 0.479]; EFU, - 0.655 [ - 0.932 to - 0.378]). A sensitivity analysis revealed similar results for CDE, TAT, and EFU. For endothelial cell density (ECD) 1 week after surgery, ECD 1 month after surgery, and central corneal thickness (CCT) 1 week after surgery, outcomes of both systems were comparable (ECD at 1 week, 0.074 [ - 0.177 to 0.325]; ECD at 1 month, 0.069 [ - 0.167 to 0.305]; CCT 1 week after surgery, 0.077 [ - 0.173 to 0.328]). No severe adverse events in patients treated with either system were reported in the studies.

CONCLUSION

Active-fluidics systems are superior to gravity-fluidics systems with respect to CDE, TAT, and EFU; no differences in postoperative ECD and CCT were observed. Future studies are required to determine the reasons for heterogeneity and to detect rare adverse events.

A prospective randomized clinical trial of active-fluidics versus gravity-fluidics system in phacoemulsification for age-related cataract (AGSPC)

BACKGROUND

To figure out the efficacy, effects, safety and patient's subjective perceptions of phacoemulsification with the active-fluidics system (AFS).

PATIENTS AND METHODS

This was a prospective, randomized, double-masked, controlled clinical study. Age-related cataract patients were recruited and randomly assigned to the AFS group and gravity-fluidics system (GFS) group in a ratio of 1:1 to have phacoemulsification. Participants were followed up at one day, one week, one month and three months postoperatively (Chinese Clinical Trial Registry, ChiCTR2100044409).

RESULTS

The overall included participants were 107 finally. The total aspiration time of the AFS group was significantly less than that of the GFS group (p = .020), while no significant difference existed in cumulative dissipated energy and estimated fluid usage between the two groups. The best corrected visual acuity was significantly better in the AFS group at one day and one week postoperatively (p = .002, p = .038 respectively). The recovery of central corneal thickening and macular superficial vasculature increase was earlier in the AFS group. The central retinal thickness was significantly higher in the GFS group at one month and three months postoperatively (p = .029, p = .016 respectively). The incidence of corneal adverse events was higher in GFS group (p = .035). No serious adverse events occurred in either group. Pain scores and the scores of Cat-PROM5 questionnaire of the AFS group were significantly lower than that of the GFS group (p = .011, p = .002 respectively).

CONCLUSION

AFS improves the efficiency, effects, safety and patients' subjective perceptions of phacoemulsification compared with GFS. It is worthwhile to promote its application in cataract surgery.KEY MESSAGESThe active-fluidics system automatically detects and maintains stable intraocular pressure at the set value.The active-fluidics system improves the efficiency, effects, safety and patients' subjective perceptions in phacoemulsification.

Active-fluidics versus gravity-fluidics system in phacoemulsification for age-related cataract (AGSPC): study protocol for a prospective, randomised, double-blind, controlled clinical trial

INTRODUCTION

The active-fluidics system is a new irrigation system of phacoemulsification that automatically detects and maintains stable intraocular pressure at the set value. This trial is designed to compare the efficacy, visual outcomes, safety and patients' subjective perceptions of cataract surgery with the active-fluidics system and gravity-fluidics system.

METHODS AND ANALYSIS

This trial will recruit 110 patients with age-related cataract at the Chinese People's Liberation Army (PLA) General Hospital (Beijing, China) and they will be randomly assigned to the active-fluidics group and gravity-fluidics group in a ratio of 1:1 to have phacoemulsification. Patients will be followed up at 1 day, 1 week, 1 month and 3 months postoperatively. The primary outcomes are the cumulative dissipated energy and best corrected visual acuity. Secondary outcomes include: estimated fluid usage, U/S time, total aspiration time, intraocular pressure, corneal endothelium parameters, retinal thickness, macular superficial vessel density, pain scores, scores of the Cataract surgery Patient-Reported Outcome Measures Questionnaire and the complication rates. The data will be independently analysed by the statistical team, who will be masked for the allocation information as participants are.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of Chinese PLA General Hospital (approval no. S2021-068-01). Informed consent will be obtained from each participant. All the results will be published in peer-reviewed journals and used for scholarly communication or technical guidance. Protocol version 1.0.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR2100044409).