Comparison of phacoemulsification surgery with 2.2 mm or 2.75 mm corneal incision

Abstract

Objective To compare the intraoperative ultrasound energy and the change of corneal endothelial cell density (CED) in 2.2 mm or 2.75 mm corneal incision phacoemulsification.Methods A prospective,randomized and controlled clinical study was conducted on 134 patients with 167 cataract eyes which were randomly divided into two groups:2.2 mm group (70 eyes of 57 patients) and 2.75 mm group (97 eyes of 77 patients).The hard degree of the nucleus was recorded.The CED was measured preoperatively,1 month and 3 months postoperatively.It was compared between the two groups.The phaco time and average energy in the surgery were recorded to calculate the effective phaco time (EPT).The intraoperative EPT was compared between the two groups.Results There was no statistically significant difference in nuclear hardness or in EPT between the two groups,but there was a positive correlation between them in both the two groups.Postoperative CED was reduced in 2.2 mm and 2.75 mm group as follows:(2510.88 ±268.81) mm-2 preoperatively and (2378.84 ± 369.93) mm-2 at 3 months postoperatively (P ＜ 0.05) in 2.2 mm group; (2524.62 ± 251.69) mm-2 preoperatively and (2388.08 ± 360.51) mm-2 at 3 months postoperatively (P ＜0.01) in 2.75 mm group.The CED trended to be stabilized 1 month postoperatively.There were no statistically significant difference in the changes of CED between the two groups (P ＞ 0.05).Conclusion Comparing with 2.75 mm incision,2.2 mm coaxial clear corneal incision is shorter in length and thus making more difficulty in the operation.However,intraoperative ultrasound energy has not increased in 2.2 mm incision system.The EPT is correlated with nucleus hardness.There is no statistically significant difference in postoperative CED loss between the two groups. Key words: Cataract; Phacoemulsification ; Incision, 2.2 mm, 2.75 mm; Cell, endothelial,corneal; Energy, ultrasonic