两种黏弹剂对超声乳化术兔角膜内皮细胞的影响

Effects of two viscoelastic substances on the rabbit corneal endothelial cells during phacoemulsification

目的:观察在超声乳化术中使用两种不同黏弹剂(Viscoat和AmviscPlus)对角膜内皮细胞的保护作用,以及角膜内皮细胞损伤的形态学分析。方法:实验于2003-06/2004-01在锦州医学院实验动物中心实验室和锦州市亚东眼科医院实验动物中心实验室进行。3.5月龄纯种日本大耳白兔12只,雌雄不限,体质量1.8～2.0kg。随机分为3组:正常对照组(为正常的兔角膜内皮细胞),Viscoat组(应用Viscoat弥散性黏弹剂),AmviscPlus组(应用AmviscPlus内聚性黏弹剂),每组4只动物。于术前、术后即刻和术后6h采用TomeyEM-1000型接触性角膜内皮显微镜进行角膜内皮细胞形态学定量测定:角膜内皮细胞密度、细胞面积、变异系数及六边形细胞(正常角膜内皮细胞形态)百分率;术后6h光镜下计算内皮细胞存活率;术后6h透射电镜下观察各组角膜内皮细胞超微结构的变化。结果:12只大耳白兔均进入结果分析。①术前各组间各项指标均无显著性差异。②术后即刻角膜内皮细胞密度和平均面积各组间无显著性差异(P>0.05);术后6h,Viscoat和AmviscPlus组细胞密度均较正常对照组降低(P<0.05),平均面积均较正常对照组增加(P<0.05)。术后即刻和6h六边形细胞百分率均低于正常对照组(P<0.05),变异系数均大于正常对照组(P<0.05)。③角膜内皮细胞活性率Viscoat组高于AmviscPlus组[(93.78±3.14)%,(80.77±3.91)%,(P<0.05)]。④角膜中央1mm区域取材的透射电镜切片示Viscoat组角膜内皮损害小于AmviscPlus组。结论:角膜内皮细胞形态学分析较细胞密度和平均面积的改变能更灵敏地反映角膜内皮的变化。在相同的手术条件下,Viscoat黏弹剂对角膜内皮细胞的保护能力优于AmviscPlus。

AIM:To compare the protective effect of the two different viscoelastic substa nces(Viscoat and Amvisc Plus) on corneal endothelial cells in phacoemulsificatio n,and analyze the morphology of corneal endotheliual cell injury. METHODS:The experiment was finished in the Central Laboratory for Experimenta l Animals,Jinzhou Medical College,and Center for Experimental Animals,Yadong Oph thalmology Hospital of Jinzhou from June 2003 to January 2004.Twelve pure Japane se flap- eared rabbits aged 3.5 months in either gender weighing from 1.8 to 2. 0 kg were randomly and equally divided into 3 groups:normal control group using the normal rabbit corneal endothelial cells,Viscoat group using Viscoat as the d iffusive viscoelastic substance,and Amvisc Plus group using Amvisc Plus as the c ohesive viscoelastic substance.Tomey EM- 1000 contact specular microscopy was u sed to evaluate the morphological indexes of corneal endothelial cells including endothelial cell density,mean cell area,percentage of hexagonal cells(normal co rneal endothelial cells) and coefficient of variation preoperatively,at 0 and 6 postoperative hours.At 6 hours after operation,the survival rate of corneal endo thelial cells was counted under light microscope,and ultrastructural changes of corneal endothelial cells were observed under transmission electron microscope. RESULTS:All the 12 rabbits were included the result analysis.① There were no significant differences in the morphological indexes among the three groups pre operatively.② Immediately after operation,the difference among groups was insig nificant in endothelial cell density and in mean cell area(P >0.05).However,at 6 hours after operation,the endothelial cell density was significantly lower in t he Viscoat and Amvisc Plus groups than in the normal control group(P< 0.05),and the mean cell area was bigger in the former two groups than in the latter group( P< 0.05).③ The survival rate of corneal endotherlial cells in the Viscoat group [(93.78± 3.14)% ]was significantly higher than that in the Amvisc Plus group[( 80.77± 3.91)% ](P< 0.05).④ Under the transmission electron microscope,at 1 mm of central cornea section,the injury degree of corneal endothelium in the Visc oat group was alleviated more significantly than that in the Amvisc Plus group. CONCLUSION:Compared with endotherlial cell density and cell area,corneal morp hology can reflect changes in corneal endothelial cells more sensitively.Viscoat is more effective in protecting endothelial cells than Amvisc Plus is under the same operation condition.