Dispase蛋白酶诱导兔眼玻璃体后脱离的实验研究

An experimental study on dispase inducing posterior vitreous detach-ment

目的:研究dispase蛋白酶诱导玻璃体后脱离的效果和安全性。方法:24只健康成年的青紫兰兔随机分为A,B,C,D4组,每组6只兔右眼均为实验眼,左眼为对照眼。A～D组实验眼玻璃体腔内分别注射dispase蛋白酶25,50,125和250U/L,对照眼均为眼用平衡盐BSS液0.0001L。注药前后行检眼镜、裂隙灯和VOLK+90D前置镜以及B超和视网膜电图(electroretinogram,ERG)检查,最后取眼球扫描电镜和透射电镜观察。结果:电镜结果A组实验眼无PVD发生;B,C2组实验眼中各有4眼发生完全性PVD,发生率为67%;D组实验眼有5眼发生完全性PVD,发生率为83%;透射电镜观察对照眼及A,B2组实验眼视网膜组织结构正常。C,D组视网膜细胞和细胞器出现水肿和变性。ERG检测A,B2组术后b波振幅与术前比较无明显降低(P>0.05);而C,D2组实验眼术后b波振幅较术前明显降低(P<0.01)。结论:浓度50U/L的dispase蛋白酶可有效地诱导PVD且对视网膜无明显的毒性作用。更高浓度的dispase蛋白酶虽然可迅速有效的诱导完全性PVD,但对视网膜有毒性作用。

· AIM: To investigate the effect and safety of dispase protease which induced posterior vitreous detachment (PVD) by intravitreous injection in rabbit eyes.· METHODS: Twenty-four young pigmented rabbits were assigned to 4 groups: Group A (25U/L), Group B (50U/L), Group C (125U/L) and Group D (250U/L). All the right eyes were injected with protease, and all the left eyes with 0.1ml BSS as controls. The eyes of rabbits were observed with biomicroscopy, B-ultrasonography and electroretinogram (ERG) in postinjection in vivo and were examined by scanning and transmission electron microscopy in vitro.· RESULTS: In eyes of Group B, C and D, the retinal surface was smooth except for the vitreous base, indicating complete PVD (67% and 83%). No PVD appeared in eyes of Group A or the control eyes. In injected eyes, the b-wave amplitudes ofERG showed no evident difference compared with those in preinjection of Group A, B and all the control eyes (P >0.05). The b-wave amplitudes of ERG significantly changed in Group C and D after the injection. Through transmission electron microscopy it was confirmed that the retina was not damaged in Group A, B and control eyes. In Group C and D, cellar edema and degeneration were present in the retina.· CONCLUSION: Vitreous injection of dispase in dose of 50U/L can efficiently and safely induce complete posterior vitreous detachment (PVD).·