方法：将年龄相关性白内障131例156眼随机分为预劈核联合乳化劈核组(A组)68例82眼和拦截劈核组(B组)63例74眼。分别使用预劈核联合乳化劈核和拦截劈核技术进行白内障超声乳化术。记录术中平均超声能量(AP)、实际超声乳化时间(U/S time)、累积能量复合参数(AECP)、平均内皮细胞密度、平均内皮细胞丢失率、术中并发症、术后1d； 1wk裸眼视力和术后1d角膜水肿等情况并进行比较。

结果：将两组中同级核硬度的亚组进行比较，A组的AP，U/S time，AECP均低于B组，差异有显著性； 且前者术后第1d角膜水肿轻于后者。术后1d裸眼视力A组优于B组，术后1wk两组裸眼视力无差异。两组术后3mo平均角膜内皮细胞密度无差异(P>0.05)，但两组术后3mo平均角膜内皮细胞丢失率差异有显著性(P< 0.05)。术中出现晶状体后囊膜破裂A组有2眼(2.4%)，B组有4眼(5.4%)。

结论：与拦截劈核相比，预劈核联合乳化劈核术中超声时间更短、能量更低、术后3mo角膜内皮细胞丢失率更少、术后早期裸眼视力更好。

METHODS:The study included 131 patients(156 eyes)with age-related cataract eyes divided into 2 groups, group A including 68 patients(82 eyes), in which phaco prechop with phaco chop was performed, and group B including 63 patients(74 eyes), in which divide and conquer was performed. The mean parameters including average power(AP), U/S time, accumulated energy complex parameter(AECP), mean endothelial cell count, mean endothelial cell loss, intraoperative complications, postoperative uncorrected visual acuity(UCVA)at 1d and 1wk, and corneal edema were reported in the two groups both preoperative and postoperative.

RESULTS:The subgroups with same grade of lens nucleus hardness were compared. Parameters such as AP, U/S time, AECP in group A were significantly less than those in group B. Postoperative corneal clarity and UCVA at 1d in group A was better than that in group B. No significant difference was found in UCVA at 1wk after operation between the two groups. The difference in mean endothelial cell count at 3mo postoperative between the two groups was statistically insignificant(P>0.05), however the difference in endothelial cell loss at 3mo postoperatively between the two groups was statistically significant(P<0.05). Two cases in groups A(2.4%)had posterior capsular rents compared to four cases(5.4%)in group B.

CONCLUSION:Compare with divide and conquer, phaco prechop with phaco chop utilized less phaco time, energy, and the rate of endothelial cell loss at 3mo postoperatively, and better early postoperative uncorrected visual acuity.