Development of Intractable Glaucoma Implant Device Using Excimer Laser

眼内压升高并伴有房水流出障碍会导致青光眼。健康人的眼压维持在正常的生理水平，在8至18毫米汞柱之间。当压力超过21毫米汞柱时，青光眼的诊断就可以被预测出来。一种新的植入物被设计用来泵送房水并调节其流出。我们研究了几种多孔聚四氟乙烯，特别是空气的渗透特性。后来我们报道了内孔直径为10μm的聚四氟乙烯多孔膜可以在20 mm的压力下被平衡盐溶液渗透。为了避免这一问题，必须开发一种孔径较小的材料，这种材料在低压下容易被水渗透。我们在其他地方报道了一种在氟碳表面上进行亲水或亲油基团的光化学取代的方法。利用这些技术使多孔聚四氟乙烯的孔内表面亲水，然后将其应用于液体分离过滤器。有了这些知识，我们能够开发出一种装置，在低压差下调节/控制房水的流速。BSS即使在300μ压力下也不能穿透PTFE 3 mm孔，但使用193 nm光子辐射(以15 mJ/cm^2发射1000次)转化了材料，允许在20 mm Hg压力下流动。BSS传输流量与OH自由基取代密度成正比。实验结果证实了这种处理方法，因为水的流动始于20毫米汞柱，动物研究表明处理后的样品是生物相容的，因此表明这种材料有可能用于眼压控制植入物。

The increased intraocular pressure with aqueous outflow failure causes glaucoma. In healthy human intraocular pressure is maintained at a normal physiological level, between 8 to 18mmHg. When pressure exceeds 21 mmHg, a diagnostic of glaucoma may be predicted.A new implant designed to pump the aqueous humor and regulate its outflow was created. We investigated several porous PTFE paying special attention to air permeation characteristics. We later reported that porous PTFE films with a 10 μm inner pore diameter could be penetrated by BSS (Balanced Salt Solution) at pressure of 20 mmHg Unfortunately, a PTFE material tends to become fragile with increased pore diameter. In order to circumvent this problem, a material with smaller pore diameters that are easily penetrated by water at low pressure must be developed. We reported elsewhere upon a method of photochemical substitution of hydrophilic or lipophilic groups on fluorocarbon surfaces. The pore inner surface of porous PTFE was made hydrophilic using these techniques that were then applied to liquid separation filters. With this knowledge we were able to develop a device that regulate/control the flow rate of the aqueous humor at a low-pressure differential. BSS cannot penetrate PTFE 3 μm pores even at 300mmHg pressure, but using 193nm photon radiation (1000 shots at 15 mJ/cm^2) transformed the material allowing flow at pressure of 20 mmHg. It was also shown that BSS transmission flow rate was proportional to OH radical substitution density. Experimental results confirmed the processing method as aqueous flow began at 20 mmHg and animal studies showed treated samples to be biocompatible, therefore indicating the potential for this material to be used in intraocular pressure control implants.