新型PHEMA一体式人工角膜植入碱烧伤兔角膜的实验研究

EXPERIMENTAL STUDY OF ONE-PIECE PHEMA KERATOPROSTHESIS IMPLANTATION IN ALKALI INJURED CORNEA IN RABBIT

目的 研究与评估聚羟乙基丙烯酸甲酯 (PHEMA)制作的一体式人工角膜在碱烧伤角膜中的生物相容性和生物愈合过程 ,并初步观察实验结果。方法 兔角膜碱烧伤 3个月后 ,形成带新生血管的角膜白斑模型。实验分两部分进行。第一部分 ,将孔隙性PHEMA材料植入角膜板层间 ,进行光镜和电镜检查 ,评价其与角膜组织生物愈合的情况。第二部分 ,将周边为多孔结构、中央为透明光学区的PHEMA一体式人工角膜植入碱烧伤兔角膜 ,进行临床试验观察。结果 所有植入物均稳定存留于角膜内 ,实验观察最长达 2 8周 ,未见排出、周围组织溶解、网脱等并发症。组织学提示炎症反应轻微 ,所有标本中均没有钙化出现。PHEMA材料孔隙中 ,2周即有成纤维细胞长入 ,并有胶原沉积 ,16周时 ,材料的大部分孔隙被成纤维细胞和胶原等细胞外基质填充 ,即与角膜组织能形成稳定的连接 ;植入的一体式人工角膜的动物观察结果较满意。结论 用PHEMA制成一体式人工角膜 ,具有良好的生物相容性 ,通过周边孔隙结构可望与碱烧伤的角膜产生“生物愈合” ,并保证植入PHEMA一体式人工角膜的稳固性。

Objective To evaluate the effect of a new one-piece PHEMA keratoprosthesis(Kpros) implanted in alkali burned rabbit corneas. Methods The experiment included two parts. In part one, the porous discs of PHEMA were inserted into the lamellar pockets of alkali-burned corneas and the results were observed clinically and histologically at various periods. In part two, seven one-piece Kpros were implanted into alkali burned rabbit corneas. The Kpros consisted of a central transparent optical area and a porous semi-transparent peripheral skirt. The surgical procedure was similar to that of penetrating keratoplasty. Clinical observations were carried out till 28 weeks. Results Both the porous discs and one-piece Kpros had been retained during the experiment. Severe complications as cataract, retro corneal membrane, retinal detachment and extrusion of material were not found until 28 weeks. There was no calcification in the samples, and inflammation was mild. Two weeks after implantation, fibroblasts and deposition of collagen were found in the pores of PHEMA discs. The fibroblasts in the pores look healthy and functionally active. The preliminary results were satisfactory. Conclusion This new one-piece Kpros had shown good biocompatibility. The porous peripheral skirt fuses well with the bed of burned cornea and proved to be stable. PHEMA materials is suitable for one-piece Kpros.