襻状支架人工角膜植入术的动物实验研究

Experimental animal studies on the implantation of keratoprosthesis with loop-support

目的 :观察兔角膜碱烧伤后新生血管性角膜白斑在应用分子定向重排PMMA襻状支架人工角膜植入后的改变情况。方法 :14只新西兰白兔 ,建立碱性角膜化学伤后偏中心新生血管性角膜白斑模型。将上述烧伤后 1个月的新生血管性角膜白斑实验兔随机分为 2组 ,每组 7只 ,分别植入分子定向重排PMMA襻状支架人工角膜 (实验组 )和Fy dorov Zyev人工角膜 (对照组 )。结果 :实验组 :术后术眼均见刺激症状和角膜水肿 ,植床角膜水肿 5～ 7d逐渐减轻 ,2w后术眼刺激症状消失。术后人工角膜在位透明 ,1眼于术后7d出现人工角膜后膜 ,3眼于术后 4～ 5w出现人工角膜前膜 ,钻除后有复发。对照组 :人工角膜支架及自体耳软骨植入 (第一期手术 )后 ,术眼充血明显 ,植床角膜水肿 ,7～ 10d后逐渐消失 ,术后 3w眼部刺激症状基本消失。人工角膜镜柱植入 (第二期手术 )后 ,术眼混合充血 ,近创缘处植床角膜水肿 ,2w后刺激症状基本消失 ,2眼于镜柱植入后 5～ 10d出现人工角膜后膜 ,清除后 1w又复发 ,3眼于术后 4～ 6w出现人工角膜前膜 ,钻除后均有复发。结论 :①襻状支架人工角膜与角膜植床之间的界面比Fydorov Zyev型人工角膜的面积小 ,能减少支架对组织的损伤。②分子定向重排PMMA具有良好的生物相容性。③动物实验证实 。

Objective:To establish the decentered neovascularization leucoma model in animals after alkali burn and observe changes after implantation of the molecular directional realignment PMMA keratoprosthesis with loop support.Methods:14 eyes of 14 New Zealand rabbits were burned by applying 1N NaOH to establish the decentered neovascularization leucoma model. One month later,the rabbits were divided into two groups. A molecule directional realignment PMMA keratoprosthesis with loop support was implanted in one eye of each rabbit in the first group,and the Fydorov Zyev type keratoprosthesis was implanted in one eye of each rabbit in the second group,which was the control group.Results:In the group with molecular directional realignment PMMA keratoprosthesis with loop support implants,the stimulative signs in the eye and corneal edema could be seen postoperatively. The corneal edema gradually decreased during the 5～7 day period after surgery. The stimulated signs disappeared within two weeks. The keratoprosthesis remained transparent postoperatively. The retrokeratoprostic membrane was formed in one eye by the seventh day postoperatively. The anterior membrane was formed in three eyes by 4 or 5 weeks after surgery and recurred after trephination. In the control group,after the support of the Fydorov Zyev type keratoprosthesis and the auricular cartilage were implanted in the first surgical stage,eye congestion and recipient bed edema were obvious for 7～10 days. The signs gradually decreased and disappeared in the third week. After the optical core of the keratoprosthesis was implanted in the second surgical stage,eye congestion and simulative signs disappeared in two weeks postoperatively. The retrokeratoprosthetic membrance appeared in three rabbits 5～10 days after the optical core was implanted,and two of them recurred in one week after the membrane was cleaned away. The anterior keratoprosthic membrane appeared in three rabbits in the 4 to 6 week periiod after the second surgical stage and recurred after trephination.Conclusion:①There was less injury to the corneal recipient bed in the first group because the interface between the keratoprosthesis with loop support and the corneal recipient bed was smaller than that for the Fydorov Zyev type keratoprosthesis.②The molecular directional realignment PMMA had good biocompatibility.③The experimental studies confirmed that the molecular directional realignment PMMA keratoprosthesis with loop support remained stable in the recipient cornea with no serious complications. This study has laid a foundation for clinical application.[