The purpose of this study was to compare the perioperative parameters of quadrant, sextant, and grid lens fragmentation patterns in femtosecond laser-assisted cataract surgery (FLACS).

Prospective randomized clinical trial.

Setting: Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China. Study population: A total of 894 eyes in 661 patients with cataracts were enrolled. Intervention or observation procedures: the nuclear density was graded according to the Emery-Little classification. Patients received lens fragmentation using a quadrant, sextant, or grid pattern after random allocation. Evaluations included intraoperative parameters, complications, and postoperative outcomes. Main outcome measurements: effective phacoemulsification time (EPT), intraoperative complications, visual acuity and intraocular pressure at one day postoperatively, as well as endothelial cell density, endothelial cell loss, and central corneal thickness at 1 week postoperatively.

In grade 1 nuclei, the mean EPT in the grid group was the shortest compared to those in the quadrant (P = 0.011) and sextant (P = 0.001) groups. In grade 2 nuclei, all 3 patterns showed no significant differences in the mean EPT (P > 0.05). In grade 3 nuclei, the sextant group revealed shorter mean EPT than the grid (P = 0.017) and quadrant (P > 0.05) groups. In grades 4 and 5 nuclei, the quadrant pattern had the shortest mean EPT among all 3 patterns (P < 0.05). The grid pattern is associated with higher intraocular pressure in hard nuclei (grades 4 and 5) than the other 2 patterns (P < 0.05).

The grid and quadrant patterns allow for shorter EPT in soft (grade 1) and hard (grades 4 and 5) nuclei, respectively. All 3 patterns can be selected for treating grade 2 nuclei. The sextant pattern may be the best option when treating grade 3 nuclei. The grid pattern should be avoided in hard nuclei combined with glaucoma or glaucoma suspect.