The Correlation between Cumulative Dissipated Energy and Corneal Endothelial Cells Loss during Ultrasonic Phacoemulsification

Abstract

Purpose: In order to provide a reference for less traumatic and more efficient cataract surgery, the surgical outcome of the relationship between cumulative dissipated energy (CDE) and corneal endothelia cell loss (ECL) during ultrasonic Phacoemulsification was investigated.Methods: A retrospective study was conducted of 119 patients who had a cataract extracted, between June 2010 and March 2011, in Hsin-Chu, Taiwan. All cataract surgeries were performed by the same surgeon, using torsional ultrasonic phacoemulsification with Alcon Infiniti Version 2.05. All of the following factors were constant: wound size and position, needle size, infusion bottle level, vacuum level and aspiration rate. The central corneal endothelial cell density (ECD) was recorded using Topcon FP-3000P, preoperatively and within 5~6 weeks after the surgery, and the ECL were then calculated for the lesion eyes of all 119 patients. The CDE for each surgery was then calculated.Results: The average age of the patients was 70±10 years. The mean total time for ultrasound (UST) was 18±11 s, mean aspiration time was 129±36 s, mean torsional amplitude was 63±15%, mean estimated fluid used was70±20 mL, mean CDE was 4.9±4.0 s, and the mean ECL of lesion eye was 14±11%. A significant linear increase in ECL of the lesion eye was observed as CDE increased. However, the correlation between age group and ECL exhibits an exponential relationship.Conclusions: This study reveals a linear correlation between mean ECL and CDE in ultrasonic phacoemulsification for the extraction of a cataract. A lower CDE generated in ultrasonic phacoemulsification may reduce the risk of corneal ECL, in cataract surgery.