Melatonin is not only synthesized by the pineal gland but by several ocular structures. This natural indoleamine is of great importance for regulating several eye processes, among which pressure homeostasis is included. Glaucoma, the most prevalent eye disease, also known as the silent thief of vision, is a multifactorial pathology that is associated to age and, often, to intraocular hypertension (IOP). Indeed IOP is the only modifiable risk factor and as such medications are available to control it; however, novel medications are sought to minimize undesirable side effects. Melatonin and analogues decrease IOP in both normotensive and hypertensive eyes. Melatonin activates its cognate membrane receptors, MT₁ and MT₂, which are present in numerous ocular tissues, including the aqueous-humor-producing ciliary processes. Melatonin receptors belong to the superfamily of G-protein-coupled receptors and their activation would lead to different signalling pathways depending on the tissue. This review describes the molecular mechanisms underlying differential functionalities that are attributed to melatonin receptors. Accordingly, the current work highlights the important role of melatonin and its analogues in the healthy and in the glaucomatous eyes, with special attention to the control of intraocular pressure.

褪黑激素不仅由松果体合成，而且由多个眼结构合成。这种天然的吲哚胺对于调节数个眼部过程非常重要，其中包括压力稳态。青光眼是一种最普遍的眼部疾病，也被称为无声窃贼，是一种多因素病理学，与年龄有关，通常与眼内高血压（IOP）有关。实际上，眼压是唯一可改变的危险因素，因此可以控制这种药物。然而，寻求新的药物以最小化不良副作用。褪黑素和类似物在血压正常和高血压的眼睛中均会降低IOP。褪黑素激活其同源膜受体MT ₁和MT ₂存在于许多眼组织中，包括产生水幽默的睫状突。褪黑激素受体属于G蛋白偶联受体的超家族，它们的激活将导致不同的信号传导途径，具体取决于组织。这篇综述描述了归因于褪黑激素受体的不同功能的分子机制。因此，当前的研究突出了褪黑激素及其类似物在健康和青光眼中的重要作用，并特别注意控制眼内压。