纤维蛋白溶解酶和Dispase蛋白酶诱导兔眼玻璃体后脱离的实验研究

An experimental study on plasmin and dispase inducing posterior vitreous detachment

目的研究纤维蛋白溶解酶和dispase蛋白酶诱导玻璃体后脱离(PVD)的作用。方法24只健康成年的青紫兰兔随机分为4组,右眼均为实验眼,左眼为对照眼。A组实验眼玻璃体腔内注射纤溶酶1U,B组纤溶酶2 U,C组dispase蛋白酶0.0125U和D组dispase蛋白酶0.025U,对照眼均为眼用平衡盐BSS液0.1 ml。注药前后行眼底镜、裂隙灯和VOLK+90D前置镜以及B超和视网膜电图(ERG)检查,最后取眼球进行光镜、扫描电镜和透射电镜观察。结果电镜结果A组2只实验眼后极部发生不完全性PVD,发生率为33.3%;B、C两组实验眼中各有4只眼发生完全性PVD。发生率为66.7%;D组实验眼有5只眼发生完全性PVD,发生率为83.3%。纤溶酶各组实验眼注药后ERG振幅与术前及对照眼比较无显著性差异(P>0.05),光镜和透射电镜观察视网膜组织结构正常,均未发现明显异常改变。而Dispase蛋白酶各组透射电镜观察视网膜细胞和细胞器出现水肿和变性。ERG检测Dispase两组实验眼术后b波振幅较术前明显降低(P<0.01)。结论玻璃体腔注射纤溶酶2U较注射1U更能有效的诱导PVD且对视网膜无明显的毒性作用。而Dispase蛋白酶虽然可迅速有效的诱导PVD,但对视网膜有明显的毒性作用。

Objective To investigate whether an injection of plasmin and dispase can induce posterior vitreous detachment（ PVD ）. Methods 24 young pigmented rabbits were assigned to four groups. All the right eyes were injected proteases. Eyes in group A received a vitreous injection of 1 unit of plasmin ; Eyes in group B received a vitreous injection of 2 unit of plasmin; Eyes in group C received a vitreous injection of 0. 0125 unit of dispase and Eyes in group D received a vitreous injection of 0. 025 unit of dispase. 24 left eyes were injected 0. 1 ml BSS as controls. The eyes of rabbits were observed with biomicroscopy, B-ultrasonography and electroretinogram （ERG） in postinjection in vivo and were examined by light microscopy, scanning and transmission electron microscopy in vitro. Results In group B and C eyes, the retinal surface was smooth except for the vitreous base, indicating complete PVD （66.7%）. In group A, eyes indicated partial PVD （33.3%） and in group D, eyes indicated complete PVD {83.3% ）. In the all control eyes, no PVD. The b-wave amplitudes of ERG showed no evident difference compared with preinjection in plasmin-group eyes and control eyes values in injected eyes （ P 〉 0.05 ）. Transmission electron microscopy and light microscopy confirmed the retinal was not damaged. In dispase-group eyes, cellar edema and degeneration was present in retina and the b-wave amplitudes of ERG were significantly changed after the injection. Conclusion Vitreous injection of plasmin in dose of 2U can efficiently induce complete posterior vitreous detachment （PVD） without retinal toxicity compared with eyes received a vitreous injection of plasmin in dose of 1U. Although vitreous injection of dispase can efficiently induce complete posterior vitreous detachment （ PVD）, the retina was damaged.