Purpose: To compare in vivo corneal endothelial cell loss (ECL) after fluid-based versus ultrasound phacoemulsification.
Methods: In this prospective randomized study, 2 groups of 21 patients underwent phacoemulsification with ultrasound (group 1) or a fluid-based system (group 2). A "divide and conquer" method with capsular bag lens implantation was performed. Cataracts graded up to nuclear opalescence 4.9 in Lens Opacities Classification System III (LOCS III) only were included. Endothelial cell density (ECD), percent hexagonality, endothelial cell area (ECA), coefficient of variation in cell size, and central corneal pachymetry were measured preoperatively, 7 days, 1 month, and 3 months after surgery. Statistical analysis was performed by using a 2-tailed Student t test.
Results: Average nuclear opalescence was identical in both groups (P = 0.908). Mean ECD was 1867 +/- 451 and 2031 +/- 400 cells/mm at 3 months postoperatively. Mean ECL was 498 +/- 415 (20.6% +/- 17.1%) and 302 +/- 302 cells/mm (13.3% +/- 13.2%) at 7 days, 589 +/- 342 (24.3% +/- 14%) and 254 +/- 214 cells/mm (11.2% +/- 9.1%) at 1 month, and 555 +/- 340 (22.9% +/- 14%) and 247 +/- 208 cells/mm (10.9% +/- 9.1%) at 3 months in groups 1 and 2, respectively. ECL was significantly lower for group 1 than for group 2 (P < 0.001) after the first postoperative month. A significant increase in ECA was also observed at the first and third (P = 0.012) postoperative months.
Conclusions: Our study showed significantly lower ECL after phacoemulsification for a fluid-based versus an ultrasound system. The fluid-based method was safer than conventional ultrasound in cataract surgery, with a nuclear opalescence graded up to 4.9 in the LOCS III classification.