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

To compare the amount of phacoemulsification ultrasound energy used between eyes undergoing femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification. 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. 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 (β = 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 (β = 0.76, 95% CI 0.66, 0.87), but not for right eyes operated on by surgeon 1 (β = 0.92, 95% CI 0.79, 1.07) or for eyes operated on by surgeons 2 or 3. 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.