甲基丙烯酸β羟乙酯水凝胶义眼台植入时巩膜包裹状态对血管化进程的影响

Effect of sclera wrapping on the progress of vascularization during 2-hydroxyethyl methacrylate hydrogel orbital implant

目的:观察甲基丙烯酸改性甲基丙烯酸β羟乙酯水凝胶义眼台植入时有无巩膜包裹对血管化进程和预后的影响。方法:实验于2003-03-01/09-01在解放军总医院眼科实验室完成。清洁级新西兰白兔64只,体质量2.0～2.5kg,雌雄不拘,随机分为巩膜包裹组和无巩膜包裹组,每组32只兔子(32只眼)。麻醉状态下分别进行眼内容剜除水凝胶义眼台植入术和眼球摘除水凝胶义眼台植入术(即水凝胶义眼台植入有无巩膜包裹)。术后0.5,1,2,3,6个月取出水凝胶义眼台,切成鼻侧和颞侧半,鼻侧半在显微镜下测量标本3,6,9,12点方位纤维血管组织生长的长度,取4个数值的平均值进行比较,制成5μm的切片,做单光子发射型计算机断层及病理检查,比较有无巩膜包裹对血管化进程和预后的影响。比较有无巩膜包裹的两种手术方法对义眼台血管化进程及预后的影响。结果:所有动物均完成了实验,64只大白兔均进入结果分析。①术后不同时间植入物纤维血管化程度显示0.5,1,2,3个月时无巩膜包裹组高于巩膜包裹组,无巩膜包裹组在3个月时已完成血管化。②单光子发射型计算机断层检查显示无巩膜包裹组示踪剂99Tcm-MDP2个月前结果与巩膜包裹组类似,3个月时在植入物内部即呈均匀分布,6个月时的表现与3个月相同;巩膜包裹组3个月时在植入物内部可见同位素浓集但分布不均匀,6个月时同位素在植入物内均匀分布。③两组植入物纤维血管增长是从周边到中心,0.5个月时已有纤维血管组织长入孔隙,孔隙中可见纤维母细胞、中性粒细胞和淋巴细胞,偶尔可见大的巨噬细胞。两组区别表现为相同时间点巩膜包裹组纤维血管填充的孔隙较无巩膜包裹组少,仅在巩膜开窗处纤维血管生长与无巩膜包裹组类似。④64只眼中仅无巩膜包裹组2只眼出现结膜裂开、义眼台暴露,两组的并发症差异无显著性(χ2=2.0645,F=0.492,P=0.151)。结论:甲基丙烯酸改性甲基丙烯酸β羟乙酯水凝胶义眼台植入兔眶腔时不用巩膜包裹血管化速度快于用巩膜包裹者,术后出现并发症的概率在统计学方面差异无显著性。

AIM： To observe whether sclera wrapping on the progress of vascularization and the prognosis during methyl methacrylate （MMA） denaturated 2- hydroxyethyl methacrylate （HEMA） hydrogel orbital implant. METHODS： All the experiments were completed in the ophthalmological laboratory of General Hospital of Chinese PLA from March 1^st to September 1^st in 2003. Sixty-four New Zealand male and female rabbits, weighed 2.0- 2.5 kg, were randomly divided into two groups with 32 rabbits （32 eyes）： sclera wrapping group and no sclera wrapping group. Under anesthesia, hydrogel orbital implants were implanted into the fight orbit of the rabbits with sclera wrapping or without sclera wrapping. At 0.5, 1, 2, 3 and 6 months after implantation, the implants were taken out and cut to two parts （nasal and temperal parts）. On the temperal part, the growth of fibrovascular tissue was evaluated at 4 positions （3, 6, 9 and 12 points of the implants）. Then the mean of the 4 values at each time point was compared. Single photon emission computerized tomography （SPECT） and pathological examination were also carried out on the sections of implants in order to compare the infection on prognosis and vascular progress between the twosurgical methods （with sclera wrapping or without sclera wrapping）. RESULTS： All the 64 rabbits were contributed to the experimental result. ① The extensions of vascularization in the group without sclera wrapping was higher than those in the group with sclera wrapping at the time points of 0.5, 1, 2 and 3 months. The vascularization was completed at 3 months after implantation in the group without sclera wrapping. ② SPECT examination showed that the results of radiotracer Tc-99mMDP in the group without sclera wrapping were similar to those in the group with sclera wrapping, and evenly distributed in the implants at 3 months, which were similar to the manifestations at 6 months. The isotopes n the group with sclera wrapping gradually concentrated but not evenly in the hydrogel orbital implants in vivo at 3 months, but became evenly at 6 months. ③ In both groups, fibrovascular tissue invaded the pores of the implant at 0.5 month from circumference, fibroblasts, neutrophil and lymphocytes, and occasionally huge macrophages could be observed in the pores. But at different time, the group without sclera wrapping filled more pores than the other group. ④ In the experiment, only 2 of the 64 rabbits had conjunction exposure, but the others healed well, and the complications had no significant difference between the two groups （X^2=2.064 5, F=0.492, P=0.151）. CONCLUSION： The velocity of vascularization when MMA denaturated HEMA hydrogel orbital implant without sclera wrapping is greater than with sclera wrapping, and the proportion of postoperative complication has no significant differences.