Comparative analysis of three different calibers phacoemulsification needles in the clinical application

Objective To study and analyze the effect of using three sizes of phacoemulsification needles with different calibers in phacoemulsification on effective phacoemulsification time (EPT),corneal astigmatism in optic axis,corneal endothelial cell count,incidence of corneal edema and vision after phacoemulsification surgery.Methods The study included 180 age-related cataract eyes of 167 cases,which matched Grade Ⅲ nucleus (Emery criterion).They were divided into 3 groups randomly,who underwent phacoemulcification with different needles.In Group A the 18G needles were used,Group B 19G,Group C 20G.Each group was used the same kind of phacoemulsification needle and incision.The EPT,the change of corneal endothelial cell count,the corneal edema incidence at 1 day after surgey,the corneal astigmatism in optic axis and the vision were recorded after surgery.The patients were followed up for 3 months.Results There were statistically significant differences among three groups in EPT (P ＜ 0.05).There was a statistically significant change in postoperative corneal endothelial cell count in group B and group C (P ＜ 0.05),but not in group A(P ＞ 0.05).There were statistically significant differences between the three group in corneal edema incidence at 1 day after the surgery (P ＜ 0.05).The differences in corneal astigmatism in optic axis among the three groups at 1 week after the surgery were statistically significant (P ＜ 0.05),but not at 1 m and 3ms postoperatively(P ＞ 0.05).There were statistically significant differences in vision at 1 d,1w,1 ms after the surgery among three groups (P ＜ 0.05),but there were no significant differences at 3 month postoperatively(P ＞ 0.05).Conclusion While using three sizes of phacoemulsification needles with different calibers in phacoemulsification,we found that for the same nuclear hardness,the smaller caliber used in the surgery,the longer EPT we needed and the poorer efficiency of phacoemulsification.It may lead to lower corneal endothelial cell count and severer corneal endothelium hurt.Moreover,the edema of incision will increase the incidence of corneal astigmatism in early stage after surgery. Key words: Cataract;  Phacoemulsification needle;  Caliber;  Corneal astigmatism;  Optic axis;  Vision, after surgery