Comparison of ultrasound energy consumption between low-energy femtosecond laser-assisted cataract surgery and conventional phacoemulsification cataract surgery in patients with different cataract densities.

PURPOSE: Femtosecond laser-assisted cataract surgery (FLACS)'s effect on reducing ultrasound energy, accumulated with cumulative dispersed energy (CDE) units, still remains controversial. This study aims to evaluate the effect of low-energy FLACS on CDE with that of conventional phacoemulsification surgery (CPS) in different cataract densities from multiple surgeons. METHODS: It was a retrospective case-control study. Total 629 eyes receiving either low-energy FLACS (performed with Ziemer LDV Z8 platform) or CPS were divided into two groups according to preoperative grading of Lens Opacity Classification System III (LOCSIII): milder and harder cataract group. The mean CDE were compared in different cataract densities and surgeons. A linear regression analysis was performed to evaluate the effect of using low-energy FLACS on CDE in harder cataract cases. RESULTS: We found overall CDE had no significant difference between two surgeries. However, low-energy FLACS led to a significantly lower CDE in patients with harder cataracts than CPS (18.47 ± 4.32 vs. 12.96 ± 2.34; p < 0.001). Similar results were observed in the three surgeon subgroups and in linear regression analysis and no significant difference of the effect accounting for surgeons. Moreover, low-energy FLACS results in a reduction of energy consumption comparing to CPS and has endothelial sparring effect in patients with harder cataracts. CONCLUSIONS: The reduced energy consumption was observed by using low-energy FLACS irrespective of surgeons' experience or the approaches adopted in patients with harder cataracts. Therefore, we can have more confidence to suggest this innovative platform to the patients in such cases.

Comparative Study of Safety Outcomes Following Nucleus Disassembly with and without the miLOOP Lens Fragmentation Device During Cataract Surgery.

Purpose: To determine the effect of a microinterventional lens prefragmentation wire loop device (miLOOP®; Carl Zeiss Meditec AG, Oberkochen, Germany), on adverse events (AEs), cumulative dispersed energy (CDE), and vision outcomes when used before phacoemulsification of high-grade mature cataracts. Setting: Three ambulatory surgical centers in the Peoria, IL region. Design: Retrospective comparative consecutive case series; single-surgeon. Methods: Patient outcomes were compared before and after introduction of miLOOP-assisted lens fragmentation prior to phacoemulsification during cataract surgeries performed 2016‒2020. The primary outcome was intraoperative AE rate/type. Secondary outcomes included ultrasound cumulative dispersed energy (CDE) administered during phacoemulsification, postoperative AEs, and best-corrected visual acuity (BCVA). Results: Data from 765 subjects (mean age 72.9 years; 1025 eyes) comprised 524 conventional lens disassembly (Control) eyes and 501 Device eyes. One hundred percent of the cataracts in both groups were advanced WHO Grade 3+ nuclei. Significantly fewer intraoperative AEs occurred in the Device group versus Controls (2.2% and 6.3% of eyes, respectively; p=0.0011). Postoperative AE rates were comparable between groups (Controls=2.9%, Device=3.5%). Mean CDE from ultrasound was significantly reduced by 21% when the microfilament loop device was used for nuclear disassembly (9.6±5.2 CDE units) versus Controls (11.6±6.4 CDE units; p<0.0001). Median postoperative BCVA was 20/25 Snellen (0.091 logMAR) in both groups. More than 70% of both Control and Device eyes had postoperative BCVA better than 20/30 Snellen. Conclusion: Microinterventional lens fragmentation was associated with lower ultrasound energy use and improved intraoperative safety than traditional unassisted surgery of advanced high-grade cataracts, while maintaining similarly acceptable postoperative complication rates and BCVA functional outcomes.

Comparison of cumulative dispersed energy between conventional phacoemulsification and femtosecond laser-assisted cataract surgery with two different lens fragmentation patterns.

The purpose of the study is to compare the total ultrasound power used between eyes undergoing different lens fragmentation patterns of femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification surgery (CPS). A total of 506 patient eyes underwent preoperative grading of lens opacity using the Lens Opacity Classification System III (LOCSIII). The eyes were divided into two subgroups: subgroup 1 had a LOCSIII grade of 1-3, and subgroup 2 had a LOCSIII grade of 4-6. The eyes underwent FLACS (LenSx) for clear corneal wound, capsulotomy, and lens fragmentation. Either a grid pattern or radial pattern was used for lens fragmentation. The eyes received one of the following three treatments: (1) CPS without femtosecond laser assistant, (2) FLACS with a grid pattern (FGP) lens fragment, or (3) FLACS with a quadrant pattern (FQP) lens fragment. The mean cumulative dispersed energy (CDE) for each subgroup and treatment was evaluated. The mean CDE was lower in the two FLACS groups (1.21±1.91 in FGP and 1.22±1.92 in FQP) than that in the CPG group (2.67±2.84). In subgroup 1, CDE was higher in the CPG group (1.54±1.18) as compared with the FLACS groups (0.16±0.31 in FGP and 0.74±1.17 in FQP; P<0.001). In subgroup 2, CDE was higher in the CPG (6.47±3.46) as compared with the FLACS groups (2.74±2.21 in FGP and 5.34±2.17 in FQP; P<0.001). CDE was lower in the two FLACS groups than that in the CPS group, and CDE was the lowest with FGP in both subgroups 1 and 2.

Comparison of cumulative dispersed energy (CDE) in femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification.

PURPOSE: To compare the amount of phacoemulsification ultrasound energy used between eyes undergoing femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification. METHODS: One eye of consecutive patients undergoing routine non-complicated phacoemulsification from January 2014 to December of 2015 was included in the analysis. FLACS was performed using the Alcon LenSx. Linear regression was used for analysis with type of surgery (FLACS versus conventional phacoemulsification) as the exposure and cumulative dispersed energy (CDE) as the outcome variable. Age, surgeon, eye side, and eye sequence (first versus second eye) were covariates. RESULTS: A total of 1159 surgeries met inclusion criteria. The average age of the cohort was 70.6 (SD 8.6) years, 590 cases (51%) were performed by surgeon 1, and 582 cases (50%) were right eyes. Overall, FLACS resulted in significantly lower CDE as compared to conventional phacoemulsification (ß = 0.89, 95% CI 0.83, 0.95). When stratified by eye side and surgeon, FLACS performed on left eyes operated on by surgeon 1 resulted in lower CDE as compared to conventional phacoemulsification (ß = 0.76, 95% CI 0.66, 0.87), but not for right eyes operated on by surgeon 1 (ß = 0.92, 95% CI 0.79, 1.07) or for eyes operated on by surgeons 2 or 3. CONCLUSIONS: The use of FLACS on the Alcon LenSx platform results in a small decrease in phacoemulsification energy as compared to conventional phacoemulsification in certain cases. Further study assessing optimal laser settings and surgical technique is necessary.