Glaucomatous visual field progression has both personal and societal costs and therefore has a serious impact on quality of life. At the present time, intraocular pressure (IOP) is considered to be the most important modifiable risk factor for glaucoma onset and progression. Reduction of IOP has been repeatedly demonstrated to be an effective intervention across the spectrum of glaucoma, regardless of subtype or disease stage. In the setting of approval of IOP-lowering therapies, it is expected that effects on IOP will translate into benefits in long-term patient-reported outcomes. Nonetheless, the effect of these medications on IOP and their associated risks can be consistently and objectively measured. This helps to explain why regulatory approval of new therapies in glaucoma has historically used IOP as the outcome variable. Although all approved treatments for glaucoma involve IOP reduction, patients frequently continue to progress despite treatment. It would therefore be beneficial to develop treatments that preserve visual function through mechanisms other than lowering IOP. The United States Food and Drug Administration (FDA) has stated that they will accept a clinically meaningful definition of visual field progression using Glaucoma Change Probability criteria. Nonetheless, these criteria do not take into account the time (and hence, the speed) needed to reach significant change. In this paper we provide an analysis based on the existing literature to support the hypothesis that decreasing the rate of visual field progression by 30% in a trial lasting 12–18 months is clinically meaningful. We demonstrate that a 30% decrease in rate of visual field progression can be reliably projected to have a significant effect on health-related quality of life, as defined by validated instruments designed to measure that endpoint.

青光眼视野的发展既有个人成本，也有社会成本，因此对生活质量产生严重影响。目前，眼压（IOP）被认为是青光眼发作和进展的最重要的可改变的危险因素。反复证明，降低IOP可以有效地干预青光眼，无论其亚型或疾病阶段如何。在降低眼压的疗法获得批准的情况下，预期对眼压的影响将转化为患者长期报告的结局获益。尽管如此，可以始终如一地客观地测量这些药物对眼压的作用及其相关风险。这有助于解释为什么青光眼新疗法的监管批准历来使用IOP作为结果变量。尽管所有批准的青光眼治疗方法都可降低眼压，但是尽管进行了治疗，患者仍经常继续进展。因此，开发通过降低IOP以外的机制保持视觉功能的治疗方法将是有益的。美国食品和药物管理局（FDA）表示，他们将接受使用青光眼改变概率标准的临床上有意义的视野进展定义。但是，这些标准未考虑达到重大更改所需的时间（因此也没有考虑速度）。在本文中，我们基于现有文献进行了分析，以支持以下假设：在持续12-18个月的试验中，将视野进展速度降低30％具有临床意义。