Although once daily anti-glaucoma drug therapy is a current clinical reality, most therapies require multiple dosing and there is an unmet need to develop convenient, safe, and effective sustained release drug delivery systems for long-term treatment to improve patient adherence and outcomes. One of the first sustained release drug delivery systems was approved for the reduction of intraocular pressure in glaucoma patients. It is a polymeric reservoir-type insert delivery system, Ocusert™, placed under the eyelid and on the ocular surface for zero-order drug release over one week. The insert, marketed in two strengths, released pilocarpine on the eye surface. While many clinicians appreciated this drug product, it was eventually discontinued. No similar sustained release non-invasive drug delivery system has made it to the market to date for treating glaucoma. Drug delivery systems under development include punctal plugs, ring-type systems, contact lenses, implants, microspheres, nanospheres, gels, and other depot systems placed in the extraocular, periocular, or intraocular regions including intracameral, supraciliary, and intravitreal spaces. This article discusses the advantages and disadvantages of the various routes of administration and delivery systems for sustained glaucoma therapy. It also provides the reader with some examples and discussion of drug delivery systems that could potentially be applied for glaucoma treatment. Interestingly, one intracamerally injected implant, Durysta™, was approved recently for sustained intraocular pressure reduction. However, long-term acceptance of such devices has yet to be established. The ultimate success of the delivery system will depend on efficacy relative to eye drop dosing, safety, reimbursement options, and patient acceptance. Cautious development efforts are warranted considering prior failed approaches for sustained glaucoma drug delivery. Neuroprotective approaches for glaucoma therapy including cell, gene, protein, and drug-combination therapies, mostly administered intravitreally, are also rapidly progressing towards assessment in humans.

尽管每日一次的抗青光眼药物治疗是目前的临床现实，但大多数治疗需要多次给药，并且尚未满足开发方便、安全、有效的持续释放药物递送系统的长期治疗需求，以提高患者的依从性和结果。第一个缓释药物输送系统被批准用于降低青光眼患者的眼内压。它是一种聚合物储库型插入递送系统 Ocusert™，放置在眼睑下方和眼表上，可在一周内实现零级药物释放。该插入物以两种强度销售，在眼睛表面释放毛果芸香碱。尽管许多临床医生赞赏这种药物，但它最终被停产。迄今为止，还没有类似的缓释非侵入性药物输送系统上市用于治疗青光眼。正在开发的药物递送系统包括泪点塞、环形系统、隐形眼镜、植入物、微球、纳米球、凝胶以及放置在眼外、眼周或眼内区域（包括前房内、睫状体上和玻璃体内空间）的其他储库系统。本文讨论了青光眼持续治疗的各种给药途径和递送系统的优点和缺点。它还为读者提供了一些可能应用于青光眼治疗的药物输送系统的示例和讨论。有趣的是，一种前房注射植入物 Durysta™ 最近被批准用于持续降低眼内压。然而，此类设备的长期接受度尚未确定。输送系统的最终成功将取决于与滴眼剂剂量、安全性、报销选项和患者接受度相关的功效。考虑到先前失败的持续青光眼药物输送方法，需要谨慎的开发工作。青光眼治疗的神经保护方法，包括细胞、基因、蛋白质和药物组合疗法，主要是玻璃体内给药，也正在迅速进展到人体评估。