FLACS and dense cataract
Randomised, controlled study finds grid pattern reduces phaco time and endothelial cell loss.
Fragmenting very dense cataract nuclei with a femtosecond laser using a grid pattern before phacoemusification significantly reduced effective phaco time (EPT) and endothelial cell count loss (ECC) compared with manual phacoemulsification or femtosecond laser-assisted cataract surgery (FLACS) using a 16-segment fragmentation approach, Soon-Phaik Chee MD told the 36th Congress of the ESCRS in Vienna.
In a prospective, randomised, controlled study, Dr Chee and colleagues at the Singapore National Eye Centre assigned 94 patients with nuclear cataracts of LOCS III NO grade 5, 6 or more to receive manual phacoemulsification, FLACS using a 600-micron grid fragmentation pattern (FLACS grid) or FLACS using a 16-segment pattern (FLACS 16) followed by phacoemulsification in a 2:1:1 ratio.
All FLACS patients were treated with a Victus femtosecond laser (Bausch + Lomb, Munich, Germany), and all patients received phacoemulsification using a Stellaris system (Bausch + Lomb, Rochester, New York, USA). All procedures were done by Dr Chee using a direct phaco chop technique. The study examined corneal safety using the three approaches, examining effective phaco time and endothelial cell loss one month after surgery.
The study found nuclear density and treatment method both affected effective effective phaco time, Dr Chee reported. Perhaps not surprisingly, the 49 cases with NO5-6 required significantly less mean phaco time than the 44 of higher than grade 6 (p<0.005) regardless of treatment method.
However, while the 22 patients in the FLACS grid group had a statistically significantly lower effective phaco time than the 71 patients in combined manual and FLACS 16 groups (p=0.043), there was no significant effective phaco time difference between the two FLACS groups, or between the manual phaco and combined FLACS groups.
Similarly, the FLACS grid group showed significantly less endothelial cell loss than manual phaco (mean 173 v 305, p=0.018), but there was no significant difference between FLACS groups, or manual phaco and the combined FLACS groups. No significant difference in endothelial cell loss was found between the NO5, 6 group and the NO>6 group.
These results vary from two non-randomised studies in the literature, which found reduced effective phaco time and endothelial cell with FLACS, Dr Chee noted. However, these studies examined softer cataracts, and used 300-micron grid patterns and a stop-and-chop phaco approach, which may have influenced the outcomes (Hatch KM et al. J Cataract Refract Surg. 2015;41:1833-1838. Chen X et al. J Cataract Refract Surg. 2017;42(4):486-491.).
“FLACS grid but not FLACS 16 segment significantly reduced mean effective phaco time and lowered mean endothelial cell loss at one month compared with manual phacoemulsification in dense cataracts,” Dr Chee concluded.