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1 粘稠剂的种类及其特点1.1 透明质酸钠 由公鸡鸡冠、脐带或链球菌培养物等提取的一种大分子粘多糖,分子量为100～380万。特点是分子量大,有一定弹性,维持前房效果好。其在眼内可发生酶的降解,随时间延长可排出眼外。但其存留眼内可致眼压升高,甚至引起青光眼。另外,该剂制造工艺复杂,价格昂贵,对角膜内皮细胞有不同程度的毒性作用。1.2 羟丙基甲基纤维素 由棉花和树木中提取,可溶于水,溶解度随温度而变化,可行高压消毒,可在室温下保存,价格低廉。其分子量7～10万,因而涂敷作用好。缺点为在眼前段不能代谢,容易阻塞小梁网,在前房内存留易引起眼压升高,维持前房
A variety of viscous agents and their characteristics 1.1 Sodium hyaluronate from the cockscomb, umbilical cord or streptococcal culture extracted a macromolecular mucopolysaccharide, the molecular weight of 100 to 380 million. Characterized by large molecular weight, there is a certain flexibility to maintain anterior chamber effect. It occurs in the eyes of enzyme degradation, with time can be excreted. However, the retention of intraocular pressure can cause intraocular pressure, and even cause glaucoma. In addition, the agent manufacturing process is complex, expensive, corneal endothelial cells have varying degrees of toxic effects. 1.2 Hydroxypropyl methyl cellulose extracted from cotton and trees, soluble in water, solubility changes with temperature, feasible high pressure disinfection, can be stored at room temperature, the price is low. The molecular weight of 7 to 10 million, so the coating effect. Shortcomings in the anterior segment can not be metabolized, easy to block the trabecular meshwork, easy retention in the anterior chamber caused by increased intraocular pressure, to maintain the anterior chamber