A Prospective Comparative Study of Surgical Outcomes between Femtosecond Laser-Assisted Cataract Surgery and Conventional Phacoemulsification in Dense Cataracts: A 12-Month Follow-Up

Objective: To compare the cumulative dissipated energy (CDE) and long-term corneal endothelial cell loss (ECL) between femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification cataract surgery (CPCS) in patients with very dense cataracts over 12 months. Materials and Methods: This prospective comparative study included patients aged 40-85 years with unilateral or bilateral cataracts of nuclear opalescence grade ≥5 according to the Lens Opacities Classification System III. Participants were consecutively recruited, with surgical technique and surgeon assigned according to a predetermined allocation table. In bilateral cases, each eye underwent a different surgical technique performed by a different surgeon (contralateral-eye design). Primary outcomes were CDE and ECL at 1, 3, 6, and 12 months postoperatively. Results: A total of 55 patients (88 eyes) were included (45 CPCS and 43 FLACS). Mean CDE did not differ significantly between CPCS and FLACS in the overall cohort (18.48 vs. 21.18, p=0.38) or the bilateral subgroup (16.83 vs. 17.52, p=0.78). At 1 month, ECL was significantly greater with FLACS than CPCS (199.33±221.14 vs. 76.75±229.08 cells/mm², p=0.04), corresponding to 8.50% and 2.18%, respectively. No significant differences were observed at 3, 6, or 12 months (all p≥0.39). The bilateral subgroup showed a similar pattern without significant differences between techniques. Conclusion: FLACS did not demonstrate a statistically significant reduction in CDE compared with CPCS. The greater early ECL with FLACS was transient and was not sustained through 12 months, suggesting no long-term endothelial advantage over CPCS in very dense cataracts.