人工角膜及其相关材料

Artificial cornea and related materials

学术背景:对于同种异体角膜移植失败的患者,人工角膜移植便成了复明的惟一希望。人工角膜的研究虽然已经跨越2个世纪,但由于各种因素限制,角膜植入术仍然只能在少数中心开展。近年来,由于相关学科的飞速发展,人工角膜也进入了快速发展时期。目的:从材料选择、片型设计、材料改性以及临床试验等角度进行叙述,比较不同结构人工角膜各自特点,并指出目前人工角膜所存在的主要问题,对理想的人工角膜提出了新的见解。检索策略:作者应用计算机检索中国全文期刊数据库(CNKI),Springer,EI,Blackwell数据库1993-01/2007-12与人工角膜相关文献。所用中文检索词有"人工角膜、角膜穿透术";英文检索词包括"artificialcornea,penetrating keratoplasty"。纳入标准:文章内容与人工角膜材料、片型设计、临床研究有关。排除标准:较为陈旧,重复性研究。文献评价:共检索到86篇相关文献,68篇文献符合上述要求,其中12篇为综述性文献,37篇为基础性研究文献,19篇为临床研究文献,从中选择30篇进行综述。资料综合:人工角膜材料包括光学镜柱材料(水凝胶、聚甲基丙烯酸甲酯、硅凝胶、玻璃)和支架材料(氟碳聚合物、羟基磷灰石、生物材料)。材料改性包括材料化学改性、材料表面处理、材料表面修饰、材料表面等离子处理。不同的角膜片型设计中,较为成功的是AlphaCor和Osteo-Odonto,并获得了美国食品药品管理局批准,进入临床阶段。结论:提高人工角膜与组织黏附度,减少并发症是长期研究的重点领域,而材料选择、材料改性、片型设计等是解决的关键。

BACKGROUND： As for the patient who fails homologous corneal implantation, the only alternative for restoring vision is artificial cornea. Although the study of artificial cornea has been straddling for two centuries, however, the surgery can be only carried out in a few special centers due to the limiting factors. In recent years, as the rapid development of relevant disciplines, artificial cornea has entered a rapid developing period. OBJECTIVE： To illustrate the material choice, structure, material modification and clinical trials of the artificial cornea, compare the characteristics of different structures artificial cornea, point out the current disadvantages of each kind of cornea, and propose a reasonable prospect to the ideal artificial cornea. RETRIEVAL STRATEGY： A computer-based search of China Full-text Journal Database, Springer, EI, Blackwell Database was undertaken to identify the articles published from January 1993 to December 2007, with the key words of ＂artificial cornea, penetrating keratoplasty＂ in both Chinese and English. Inclusive criteria： articles related to the material, design and clinical study of artificial cornea. Exclusive criteria： outdated and repetition researches. LITERATURE EVALUATION： A total of 86 articles were collected, including 68 met the inclusive criteria, in which there were 12 review articles, 37 basic researches and 19 clinical researches. Finally 30 articles were selected for reviews. DATA SYNTHESIS： The materials of artificial cornea include optical materials （hydrogel, polymethyl methacrylate, silica gel, glass） and scaffold materials （fluorine-carbon polymer, hydroxyapatite ceramic, biomaterial）. Materials modification consists of chemical modification, surface treatment, and surface plasma treatment, etc. The successful design models of artificial cornea are AlphaCor and Osteo-Odonto, which have been approved by the American Food and Drug Administration and have applied on the clinical practice. CONCLUSION： The further study should be focused on elevating the attachment between artificial cornea and tissue, and reducing complications. The choice, modification and design of the materials are the key solvement.