方法：本研究为前瞻性、随机临床病例研究。随机选择135例的年龄相关性白内障患者接受同轴微小切口白内障手术，首先根据LOCS Ⅲ分级标准按晶状体核混浊程度(nuclear opacity，NO)分为三组：NO2组、NO3组及NO4组，每组患者又依据术中使用劈核方式不同再分成三组： phaco-chop组，divide-and-conquer组及stop-and-chop组。观察指标包括术前及术后1mo最佳矫正视力(best corrected visual acuity，BCVA)、中央角膜厚度(central corneal thickness，CCT)及角膜内皮细胞计数(endothelial cell count， ECC)，术中超声时间(ultrasound time，UST)、累积消耗能量(cumulative dissipated energy，CDE)、灌注液消耗量(esstimated fluied used，EFU)及手术并发症。

结果：在晶状体核混浊程度为NO4组的同轴微小切口超声乳化术中phaco-chop组使用的UST，CDE和EFU均明显低于divide-and-conquer组和stop-and-chop组(P<0.05)，且该组术后1mo时角膜内皮丢失率也明显低于divide-and-conquer组和stop-and-chop组(P<0.05)。但术后1mo时在不同晶状体核混浊程度分组中三种劈核方式的BCVA及CCT无明显差异(P>0.05)。

结论：同轴微小切口白内障手术中三种不同的劈核方式针对轻度和中度核混浊白内障都有良好的疗效。但在重度核混浊白内障中phaco-chop技术显示出更好的超声乳化效率、更少的角膜内皮损伤。

METHODS: It was a perspective and randomized clinical trial. Totally 135 patients with age-related cataract were selected randomly and underwent MICS. According to the lens nuclear opacity(NO)of LOCSⅢ grading standards, it can be divided into 3 groups as NO2, NO3 and NO4 group. All groups were randomly subdivided into 3 groups(phaco-chop, divide-and-conquer and stop-and-chop group). The observation target included best-corrected visual acuity(BCVA), central corneal thickness(CCT)and endothelial cell count(ECC)before operation and 1mo postoperation, ultrasound time(UST), cumulative dissipated energy(CDE), estimated fluied used(EFU)in operation and complications.

RESULTS:In lens nuclear opacity NO4 coaxial micro-incision phacoemulsification, phaco-chop group showed significantly less UST, CDE and EFU than the divide-and-conquer and stop-and-chop groups(P<0.05)and the ratio of endothelial cell loss was significantly lower in the phaco-chop group than in the divide-and-conquer and stop-and-chop groups 1mo after surgery(P<0.05). However, after 1mo surgery, BCVA and CCT among three chop technique groups in different lens nuclear opacity groups had no significant differences(P>0.05).

CONCLUSION: All 3 techniques may be effective for coaxialmicroincision cataract surgery in mild and moderate nuclear opacity cataracts. However, in eyes with severe nuclear opacity cataract, the phaco-chop technique can be more effective for phacoemulsification, and less corneal endothelial damage.