聚羟基脂肪酸和聚乳酸膜在兔青光眼滤过手术和角膜层间移植手术中的探索应用

摘要

目的 评价膜性聚羟基脂肪酸(polyhydroxyalkanoates,PHA)和聚乳酸(polylactic acid,PLA)在兔青光眼滤过手术(glaucoma filtration surgery,GFS)中的应用维持眼压(intraocular pressure,IOP)的效果,评价膜性聚羟基脂肪酸在角膜层间植入后的形态学.方法 选新西兰兔28只,其中24只随机分为6组,GFS中植入高分子材料者为实验组,实验组按植入材料辐照剂量不同又分为4个亚组:PHA-low组、PHA-high组、PLA-low组和PLA-high组,对应的膜性材料植入巩膜瓣和结膜瓣下;GFS中联合使用丝裂霉素(mitomycin C,MMC),使用者设为阳性对照MMC组:巩膜瓣和结膜瓣下使用MMC(0.2 mg/m)3 min;单纯行兔GFS而不用任何材料者设为空白对照组.三组分别于术前和术后1、3、7、14、28、84 d分别测量术眼眼压.4只角膜层间植入PHA膜,观察术后84 d角膜形态学变化.结果 术后84 d,PHA-low和PLA-high组眼压比空白对照组眼压低(P < 0.05),PHA-low和PLA-high实验组眼压与MMC组眼压近似(P > 0.05).形态学见滤过通道未被胶原纤维充填,植入材料周围胶原纤维大致平行排列.角膜层间植入PHA膜的周边胶原结构未发生明显变化.结论 膜性PHA和PLA应用于兔GFS可能促进眼压维持,效果与MMC类似.其作用机制可能是通过机械性阻隔纤维组织长入滤过通道实现的.%Objective To evaluate the effect of two polymer membranes, polyhydroxyalkanoates(PHA)and polylactic acid(PLA)during glaucoma filtration surgery(GFS),and to evaluate the morphology of membranous PHA after interlamellar implantation. Methods Twenty-eight New Zealand white rabbits were chosen and twenty-four of them were randomly divided into 6 groups(n=4):the PHA-low group,PHA-high group,PLA-low group,PLA-high group,positive control group(MMC group)and blank control group. The rabbits in each group received GFS. The corresponding polymer membranes were implanted under the scleral flap,while the MMC group was treated with 0.2 mg/mL mitomycin C(MMC) for 3 minutes,and the blank control group was treated without extra drugs. The intraocular pressure(IOP)was examined at 0 d,1 d, 3 d, 7 d, 14 d, 28 d and 84 d after GFS. The corneal layers of four rabbits were implanted with PHA membranes and the corneal morphological changes were observed after 84 d. Results The IOP of the PHA-low and PLA-high groups was lower than that of the blank control group at 84 d after GFS(P < 0.05),and was similar with that of the MMC group(P> 0.05). Morphological studies showed that there were no collagenous fibers filling in the duct, and the collagenous fibers around the membranes were generally arranged in parallel. There were no obvious changes in the peripheral collagen structure after implantation of PHA membranes between the corneal layers. Conclusions Application of PHA and PLA membranes during GFS in rabbits may maintain the level of IOP,and the effect is similar with MMC. The mechanism may be achieved through the mechanical blocking of fibrous tissue.