纤溶酶和透明质酸酶诱导猪玻璃体后脱离的比较研究

目的：研究纤溶酶和透明质酸酶诱导猪玻璃体后脱离（PVD）的有效性和安全性,比较两种酶单独应用和联合应用的效果。方法：小型猪15只随机分为A,B,C三组,每组5只,随机选取1只眼为实验眼,对侧眼为对照眼。三组实验眼玻璃体腔分别注射50U（0.1mL）透明质酸酶、0.5U（0.1mL）纤溶酶和0.5U（0.05mL）纤溶酶加50U（0.05mL）透明质酸酶,对照眼均注射平衡盐溶液（BSS）0.1ml。注药后进行裂隙灯、直、间接检眼镜、眼B超、视网膜电图（ERG）等检查,7d后摘除眼球进行光镜、透射电镜、扫描电镜检查。结果：B超检查显示A组有1只实验眼、B组有两只实验眼于注药后1d观察到部分性PVD,C组有1只实验眼于注药后1h观察到部分性PVD。B超、光镜和扫描电镜检查显示注药后7dA组和B组实验眼均见部分性PVD,C组实验眼均见完全性PVD,对照眼未见PVD。实验及对照眼注药前、后ERGa波、b波波幅均无显著性差异,光镜及透射电镜检查未见视网膜损害。结论：0.5U纤溶酶和50U透明质酸酶单独及联合应用均可快速、安全、有效地诱导猪眼玻璃体后脱离,且联合用药较单独用药诱导PVD更快速、更有效。

A comparative study on the induction of posterior vitreous detachment by plasmin and/or hyaluronidase intravitreal injection into pig eyes

· AIM: To investigate the efficacy and safety of intravitreal injection of plasmin, hyaluronidase, or the combination of the two in inducing posterior vitreous detachment (PVD).· METHODS: 15 mini-type pigs were assigned to three groups (Group A, B and C), 5 in each group. One eye of each pig was intravitreally injected with the studying agent,and the fellow eye was used as control. Group A received a vitreous injection of hyaluronidase 50U (0.1mL); group B received plasmin 0.5U (0.1mL); group C received plasmin 0.5U (0.05mL) combined with hyaluronidase 50U (0.05mL). The fellow eyes in each group were injected with 0.1mL balanced salt solution (BSS). All the pigs were examined with slit-lamp biomicroscope, direct and indirect ophthalmoscope, B-scan and electroretinograph (ERG). After 7 days, the animals were killed and the eyes were enucleated and examined with light microscope, transmission electron microscope and scanning electron microscope.· RESULTS: B-scan examination showed that one eye of Group A and two eyes of Group B had partial PVD at 1st day after injection and one eye of Group C at 1 hour after injection. On the 7th day, B-scan, light microscopy and scanning electron microscopy demonstrated that all the eyes of Group A and Group B had partial PVD, while none of the control eyes had PVD. Rank sum test for scanning electron microscopy results of all the groups showed P ＜0.005.Furthermore, the comparisons between every two groups were made. The results of analyses were as follows: P＞0.05 between the drug injected eyes of Group A and Group B, P＜0.05 between Group B and Group C, Group A and Group C.The b-wave and a-wave amplitudes of ERG showed no significant difference either between preinjection and postinjection in all groups or between the drug injected eyes and the control eyes in each group. Light microscopy and transmission electron microscopy revealed no damage to the retinal structure.· CONCLUSION: Intravitreal injection of hyaluronidase 50U or plasmin 0.5U or their combination can produce PVD effectively and quickly without retinal functional or structural toxicity. The combination of the two proteases was proved to be synergetic.