方法：对143例184眼Ⅳ级及以上核采用小切口白内障囊外摘除+人工晶状体植入术，术中随机采用手法勾刀劈核法(92眼)或双刀劈核法(92眼)，观察比较术中后囊膜破裂情况，观察比较患者术后1d，1wk，1mo的视力、角膜水肿、角膜散光情况。

结果：术中后囊膜破裂情况，勾刀劈核法(10眼)与双刀劈核法(1眼)差异有统计学意义(P<0.05)； 术后1d视力比较勾刀劈核法(92眼，0.380±0.105)与双刀劈核法(92眼，0.420±0.095)差异有统计学意义(P<0.05)； 术后1wk视力比较勾刀劈核法(84眼，0.480±0.123)与双刀劈核法(86眼，0.520±0.085)差异有统计学意义(P<0.05)； 术后1mo视力比较勾刀劈核法(60眼，0.610±0.083)与双刀劈核法(52眼，0.643±0.072)差异无统计学意义； 术后1d，1wk，1mo的角膜水肿、角膜散光情况勾刀劈核法与双刀劈核法差异无统计学意义。

结论：勾刀劈核法与双刀劈核法在小切口白内障囊外摘除+人工晶状体植入术中的应用均能有效治疗Ⅳ级及以上核的白内障，两组最主要的差异在于后囊膜破裂的情况，导致视力恢复有快慢之别，术后角膜水肿及散光情况两组无明显差异。

METHODS: We observed 143 cases(184 eyes)with grade Ⅳ or higher taken the small incision cataract extraction and intraocular lens implantation. Patients were given randomly knifed chopping with closed hook(92 eyes)or double knifed chopping(92 eyes). The intra-operative posterior capsule rupture was observed and compared. At 1d, 1wk and 1mo postoperatively, visual acuity, corneal edema and corneal astigmatism were observed and analyzed.

RESULTS:There were 10 eyes in patients accepting knifed chopping with closed hook with intra-operative posterior capsule rupture and 1 eye in patients accepting double knifed chopping. The difference between the two groups was statistically significant. The visual acuity of patients accepting knifed chopping with closed hook(92 eyes)at 1d postoperatively was 0.380±0.105, and that of patients accepting double knifed chopping(92 eyes)was 0.420±0.095; the difference between the two groups was statistically significant. The visual acuity of patients accepting knifed chopping with closed hook(84 eyes)at 1wk postoperatively was 0.480±0.123, and that of patients accepting double knifed chopping(86 eyes)was 0.520±0.085; the difference between the two groups was statistically significant. The visual acuity of patients accepting knifed chopping with closed hook(60 eyes)at 1mo postoperatively was 0.610±0.083, and that of patients accepting double knifed chopping(52 eyes)was 0.643±0.072; the difference between the two groups was not statistically significant. The differences on corneal edema and corneal astigmatism between the two methods at 1d, 1wk and 1mo postoperatively were not statistically significant.

CONCLUSION:The application of knifed chopping with closed hook and double knifed chopping in small incision extracapsular cataract extraction and intraocular lens implantation can effectively treat with cataract with grade Ⅳ or higher. The most important difference is on the capsular rupture which causes the different recover periods after the two operations. There was no significant difference on postoperative corneal edema and astigmatism.