周边视网膜冷冻联合tPA和C_3F_8玻璃体腔注射诱导玻璃体后脱离的动物实验研究

Posterior vitreous detachment induced by intravitreal injection of tissue-type plasminogen activator(t-PA) and C3F8 combined with peripheral retinal cryotherapy in the rabbit eye

目的探讨周边视网膜冷冻后玻璃体腔注射酶或/和膨胀气体诱导玻璃体后脱离(Posterior vitreous detachment,PVD)的效果、机制并观察其对视网膜的毒性作用。方法选用新西兰白兔48只,随机分为实验组和对照组。实验组I行周边视网膜冷冻及玻璃体腔内注射纤维蛋白溶解酶原激活剂(tissue plasminogen activator,tPA),实验组Ⅱ玻璃体腔单纯注射C3F80.3ml,实验组Ⅲ行周边视网膜冷冻,24小时后注射tPA25μg和C3F80.3ml。记录各实验组产生玻璃体后脱离的时间并观察眼内的反应性变化,最后行光镜和扫描电镜检查,观察各实验组用药后的组织形态学变化。结果三组均有效诱导PVD,组间两两比较差异有显著性(<0.05),实验组Ⅰ和Ⅱ眼内反应较轻,实验组Ⅲ反应最重,并有视网膜结构及功能损害。结论周边视网膜冷冻后tPA注射是诱导玻璃体后脱离安全有效的方法。单纯膨胀气体注射并非真正意义的玻璃体后脱离。酶与气体联合用药可缩短玻璃体后脱离产生时间,但容易造成视网膜药物毒性变化。

Objective To investigate the occurrence and mechanism of posterior vitreous detachment induced by intravitreal injection of tissue-type plasminogen activator and C3F8 combined with peripheral retinal cryotherapy ,and investigate its toxicity for retinal.Methods 48 New Zealand rabbits were randomly divided into experimental and control groups.Experimental groupl intravitreal injection of tissue-type plasminogen activator combined with peripheral retinal cryotherapy, experimental group2 intravitreal injection of C3F8, experimental group3 intravitreal injection of tissue-type plasminogen activator 25 μg and C3Fs 0.3ml combined with peripheral retinal cryotherapy. Investigate the occurrence time of posterior vitreous detachment and the ocular reaction ,and investigate the histological changes of retina.Results Each group can induced posterior vitreous detachment,between the groups showed significant difference（P〈0.05）.Group 1 and 2 have mild ocular reaction,but group 3 have serous ocular reaction and histological damage of retina.Conclusion Intravitreal injection of tissue-type plasminogen activator combined with peripheral retinal eryotherapy is a safe method to induce posterior vitreous detachment.but simply intravitreal injection of C3F8 can not induce real posterior vitreous detachment.The use of tissue-type plasminogen activator combined with C3F8 can shorten the occurrence time of posterior vitreous detachment but would cause retinal toxicity damage.