Determining Factors for Corneal Endothelial Cell Loss by Using Bimanual Microincision Phacoemulsification and Power Modulation

Abstract

To determine risk factors for central corneal endothelial cell loss in bimanual microincision cataract surgery by using power modulation. Prospective study: 79 eyes (70 subjects) with uncomplicated bimanual cataract surgery by using power modulation. Cataracts were graded with the LOCS III system. Specular microscopy was performed preoperatively and postoperatively (5 weeks). Endothelial cell density was calculated (CD; cells/square millimeter). Endothelial cell loss (ECL = preoperative CD - postoperative CD; cells/square millimeter) and proportional loss of cells [PLC = (ECL/preoperative CD) x 100; %)] were calculated. Phacoemulsification time (seconds) and average phacoemulsification power in foot position 3 (%) were recorded. Cataracts were moderate to high density, nuclear color = 3.96, and nuclear opalescence = 3.91. Endothelial cell loss = 196 cells/square millimeter (P < 0.0001). Proportional loss of cells = 8.12% (P < 0.0001). Average phacoemulsification power in foot position 3 was low (8.17%). Increased nuclear color and opalescence were correlated with more phacoemulsification time and higher average phacoemulsification power in foot position 3 (P < 0.0001). Endothelial cell loss and proportional loss of cells, respectively, were affected by increased nuclear color (P < 0.004, P < 0.003) and opalescence (P < 0.006, P < 0.004) but were not affected by phacoemulsification time. Average phacoemulsification power in foot position 3 had a mild effect on endothelial cell loss and proportional loss of cells (P = 0.02, P = 0.02). Despite the need for longer phacoemulsification time and increased power to emulsify denser cataracts, the amount of endothelial cell loss was only mildly affected by the average phacoemulsification power in foot position 3 and unaffected by total phacoemulsification time, showing that bimanual phacoemulsification with power modulation is an efficient and effective technique for performing cataract surgery.