Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore 639798.
Adv Healthc Mater. 2014 Feb;3(2):205-13. doi: 10.1002/adhm.201300113. Epub 2013 Jul 9.
Glaucoma drainage device (GDD) implantation is an effective method of lowering the intraocular pressure (IOP). Commonly used GDDs can be classified into nonvalved and valved. Although a stable IOP is critical, currently available devices often cause extreme IOP fluctuations: nonvalved GDDs suffer from a risk of hypotony (IOP<5 mmHg), whereas valved GDDs have a higher risk ocular hypertensive (IOP>22 mmHg). It is hypothesized that a GDD with a valve designed to open around the time of onset of the hypertensive phase, would minimize IOP fluctuation. Accordingly, a valve fabricated from a biodegradable polymer poly(L-lactide-co-ϵ-caprolactone) (PLC 70/30) is evaluated in vitro and in vivo. The pressure response is compared with its non-degradable counterpart in in vitro studies of IOP. It is also established that in vitro, the biodegradability of the valve is programmed to occur over 12 weeks. In vivo, a steady and low IOP is achieved with the biodegradable valve and the hypertensive phase is significantly attenuated compared with the commercial device. Fibrotic encapsulation of the device is also minimized with the biodegradable valve in vivo.
青光眼引流装置（GDD）植入术是降低眼内压（IOP）的有效方法。常用的 GDD 可分为无阀和有阀两种。尽管稳定的 IOP 很关键，但目前可用的装置通常会导致眼压剧烈波动：无阀 GDD 存在低眼压（IOP<5mmHg）的风险，而有阀 GDD 则存在更高的眼压升高（IOP>22mmHg）风险。据推测，一种设计为在高血压期开始时开启的带阀 GDD 可以将眼压波动降到最低。因此，评估了一种由可生物降解聚合物聚（L-丙交酯-co-ε-己内酯）（PLC 70/30）制成的阀在体外和体内的性能。在体外研究 IOP 时，将压力响应与其不可降解的对应物进行了比较。此外，还确定在体外，阀的生物降解性被编程为在 12 周内发生。在体内，使用可生物降解的阀可以实现稳定且较低的 IOP，并且与商业装置相比，高血压期明显减弱。在体内，生物可降解阀还可以最大程度地减少装置的纤维囊包裹。
