Effects of Cumulative Dissipated Energy on Corneal Endothelial Cells in Phacoemulsification Based on Nucleus Sclerosis

Purpose: To investigate changes in corneal endothelial cell (CEC) by cumulative dissipated energy (CDE) during phacoemulsification. Methods: Based on the degree of nucleus sclerosis (NS), changes in CECs were compared preoperatively and at 1 and 3 months postoperatively in 67 eyes that underwent phacoemulsification. Results: The mean CDE used during surgery was 4.30 +/- 2.31. A comparison of the surgical measurements before and 1 month after surgery revealed significant differences in the cell density (CD) and coefficient of variation (CV) (p < 0.001, 0.011, respectively). The CD showed significant differences among NS grades 2-6 (p < 0.001). The CDE increased significantly with higher NS grades (r = 0.809, p < 0.001). Within the same NS grade, there was a positive correlation between higher CDE and greater CEC loss (r = 0.559, p = 0.001). CD changes were significantly associated with increasing CDE (r = 0.612, p < 0.001). The CD loss also increased significantly from NS2 to NS6 (p < 0.001). At 3 months postoperatively, surgical measurements revealed a significant decrease in CD with increasing NS grade (p = 0.010). Conclusions: CDE increased with higher NS grades and there was a positive correlation between CDE and CEC loss. Therefore, surgeons should plan surgical techniques preoperatively to minimize CDE as NS increases. Additionally, it is important to assess CEC damage postoperatively based on surgical measurements in patients with high intraoperative CDE.