RESUMO
PURPOSE: To evaluate ultrasound (US) energy and endothelial cell loss in cataract surgery using the stop-and-chop and nuclear preslice techniques. SETTING: Vision Institute, Federal University of São Paulo, São Paulo, Brazil. METHODS: This prospective clinical trial comprised 43 patients (50 eyes) with senile nuclear cataract who were randomly assigned to 1 of 2 groups: stop-and-chop (n=26) or nuclear preslice (n=24). The groups were divided according to nuclear density (NO(3) NC(3) and NO(4) NC(4)) using the Lens Opacity Classification System III. A full ophthalmic examination including biometry, specular microscopy, and pachymetry was performed preoperatively and postoperatively. The following parameters were evaluated: age, anterior chamber depth, lens thickness, axial length, phaco time and power, effective phaco time (EPT), infusion volume, ocular inflammation, endothelial cell loss, and best corrected visual acuity (BCVA). RESULTS: Phacoemulsification time, power, and EPT were significantly higher in the stop-and-chop group. Infusion volumes did not vary significantly between the groups. A significant decrease in endothelial cell density occurred postoperatively and was similar with both techniques (stop-and-chop, 8.70%; nuclear preslice, 8.72%). The BCVA improved significantly in both groups. No significant correlations were found between endothelial cell loss and either technique. CONCLUSIONS: Ultrasound energy consumption was lower with the nuclear preslice technique. Both techniques had similar results including endothelial cell loss.
