FLACS Reduces Endothelial Cell Loss vs Phacoemulsification in Dense Cataract Treatment

Doctor doing eye surgery of patient in hospital
The FLACSg fragmentation pattern significantly lowered mean endothelial cell count loss for these patients.

Grid femtosecond laser-assisted cataract surgery (FLACS) may significantly reduce endothelial cell loss compared with manual phacoemulsification for dense cataract treatment, according to research results published in the American Journal of Ophthalmology. 

In a prospective randomized controlled study, researchers compared the outcomes of FLACS vs phacoemulsification, as well as the efficacy of 600 µm grid vs 16-segment FLACS fragmentation patterns, in the management of dense cataracts. 

Participants from the Singapore National Eye Center with nuclear density Lens Opacities Classification System III nuclear opacity grade 5 were recruited between 2016 and 2018. Participants were randomly assigned 2:1:1 to 1 of 3 treatment arms: phacoemulsification, FLACS using a grid pattern of 600 µm (FLACSg), or FLACS with a 16-segment pie pattern (FLACS16). 

The study cohort included 93 patients: 48 in the phacoemulsification group, 22 in the FLACSg group, and 23 in the FLACS16 group. Patients were primarily Chinese (93.5%), with a mean age of 74.3±8.8 years. Nuclear opacity grades 5 to 6 were most common (59.1% of participants). No significant between-group differences were noted in preoperative parameters, and no patients experienced intraoperative complications, including capsulotomy run-outs or posterior capsule ruptures. 

Following cataract removal, researchers noted significant improvements in all postoperative visual acuities, with no differences between treatment groups. There were also no significant differences in effective phacoemulsification time (EPT) between the groups, although a trend was present. When investigators separated density into nuclear opacity grade less than or more than 6, significant differences in EPT were noted. Surgery duration did not differ (16.38±4.72 minutes, 15.29±2.53 minutes, and 15.26±3.51 minutes in phacoemulsification, FLACSg, and FLACS16, respectively). 

Sixteen eyes experienced transient corneal edema postoperatively (13 mild and 3 moderate). By postoperative week 1, only 2 patients had mild edema, and none had moderate edema. There were no significant between-group differences in rates of postoperative corneal edema at day 1. 

Investigators compared preoperative and postoperative endothelial cell counts (ECCs). There were significant differences documented in postoperative ECC readings and ECC loss; however, this loss was only significant between the phacoemulsification and FLACSg groups. Using 2-way ANOVA analysis, investigators found no statistically significant differences in ECC loss between the 2 nuclear density groups. 

Results of a multiple regression analysis of factors for ECC loss resulted in significant findings for treatment group, EPT, and surgery duration, following adjustment for age, sex, anterior chamber depth, lens thickness, and nuclear density. 

Study limitations include the short follow-up duration, the relatively small sample size, and the use of nuclear appearance for cataract grading.

“FLACSg but not FLACS16 significantly lowered the mean ECC loss at 1 month compared with manual [phacoemulsification] using the in situ chop technique when managing dense cataracts,” the researchers concluded. “The EPT and duration of surgery were other important factors that influenced ECC loss.” 

Disclosure: Multiple study authors declared affiliations with the biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.  


Chee S-P, Yang Y, Wong MHY. Randomized controlled trial comparing femtosecond laser-assisted with conventional phacoemulsification on dense cataracts. Am J Ophthalmol. 2021;229(9):1-7. doi:10.1016/j.ajo.202.12.024