超声针头斜面向下乳化劈裂技术在白内障超声乳化术中的应用

目的评估超声针头斜面向下乳化劈裂技术的手术效果,探讨超声乳化术中角膜内皮细胞机械性损伤的机制。方法对251眼白内障施行超声乳化及人工晶体植入术。术中采用超声针头斜面向下乳化劈裂技术127眼（A组）,其中Ⅱ级核28眼,Ⅲ级核69眼,Ⅳ～Ⅴ-级核30眼。采用传统的超声针头斜面向上乳化劈裂技术124眼（B组）,其中Ⅱ级核31眼,Ⅲ级核65眼,Ⅳ～Ⅴ-级核28眼。对两组的累计能量复合参数及术后6个月角膜内皮细胞丢失率分别对照研究。结果A组累计能量复合参数：Ⅱ级核（2.7±0.5）秒;Ⅲ级核（11.9±2.1）秒;Ⅳ～Ⅴ-级核（30.2±8.1）秒。角膜内皮细胞丢失率：Ⅱ级核（5.1±0.6）%;Ⅲ级核（8.9±0.4）%;Ⅳ～Ⅴ-级核（12.5±1.6）%。B组累计能量复合参数：Ⅱ级核（2.6±0.4）秒;Ⅲ级核（12.2±2.5）秒;Ⅳ～Ⅴ-级核（31.7±8.9）秒。角膜内皮细胞丢失率：Ⅱ级核（5.0±0.5）%;Ⅲ级核（11.2±0.8）%;Ⅳ～Ⅴ-级核（20.6±1.4）%。Ⅱ级核组间差异无统计学意义（P〉0.05）,Ⅲ级核组间差异有统计学意义（P〈0.05）,Ⅳ～Ⅴ-级核组间差异有统计学意义（P〈0.01）。结论 超声乳化术中采用超声针头斜面向下乳化劈裂技术可有效地降低角膜内皮细胞的损失率。对于硬核白内障的超声乳化，采用此技术更有利于对角膜内皮细胞的保护。

Bevel-down phaco chop in phacoemulsification

Objective To evaluate the outcomes of bevel-down phaco-chop and study the mechanism which results in the loss of corneal endothelium in phacoemulsification. Methods 251 eyes accepting phacoemulsification were divided into two groups. The technique of bevel-down phaco-chop was performed on 127 eyes in group A. The nucleus density grade was Ⅱ in 28,Ⅲ in 69,and Ⅳ-Ⅴin 30 eyes. The other 124 eyes were divided into group B and on which the traditional technique of bevel-up phaco-chop was performed. The nucleus density grade was Ⅱ in 31, Ⅲ in 65, and Ⅳ- Ⅴ in 28 eyes. The differences of accumulated energy complex（AEC） and corneal endothelium loss （CEL） over 6 months post-operation were compared between the 2 groups. Results In group A, the AEC was 2.7 ± 0.5, 11.9 ± 2.1 and 30.2 ± 8.1 seconds; the CEL was （5.1 ±0.6） %, （8.9 ± 0.4）% and （12.5±1.6）% in eyes with grade Ⅱ, Ⅲ and Ⅳ-Ⅴ nucleus density respectively. In group B, the AEC was 2.6±0.4, 12.2±2.5 and 31.7 ± 8.9; the CEL was （5.0± 0.5）%, （11.2±0.8）% and （20.6± 1.4）% respectively. The CEL had no difference in the eyes with grade Ⅱ nucleus density（P 〉 0.05）, but had differences in the eyes with grade Ⅲ and Ⅳ-Ⅴ nucleus densities between the 2 groups（ P 〈 0.05）. Conclusion Bevel-down phaco-chop can reduce damage to corneal endothelial cells and is more useful in hard cataract phacoemulsification.