Macular edema consists of intra- or subretinal fluid accumulation in the macular region. It occurs during the course of numerous retinal disorders and can cause severe impairment of central vision. Major causes of macular edema include diabetes, branch and central retinal vein occlusion, choroidal neovascularization, posterior uveitis, postoperative inflammation and central serous chorioretinopathy. The healthy retina is maintained in a relatively dehydrated, transparent state compatible with optimal light transmission by multiple active and passive systems. Fluid accumulation results from an imbalance between processes governing fluid entry and exit, and is driven by Starling equation when inner or outer blood-retinal barriers are disrupted. The multiple and intricate mechanisms involved in retinal hydro-ionic homeostasis, their molecular and cellular basis, and how their deregulation lead to retinal edema, are addressed in this review. Analyzing the distribution of junction proteins and water channels in the human macula, several hypotheses are raised to explain why edema forms specifically in the macular region. “Pure” clinical phenotypes of macular edema, that result presumably from a single causative mechanism, are detailed. Finally, diabetic macular edema is investigated, as a complex multifactorial pathogenic example. This comprehensive review on the current understanding of macular edema and its mechanisms opens perspectives to identify new preventive and therapeutic strategies for this sight-threatening condition.

黄斑水肿由黄斑区域的视网膜内或视网膜下积液组成。它发生在许多视网膜疾病的过程中，并可能导致中央视力的严重损害。黄斑水肿的主要原因包括糖尿病，视网膜分支和视网膜中央静脉阻塞，脉络膜新生血管形成，后葡萄膜炎，术后炎症和中央浆液性脉络膜视网膜病变。健康的视网膜保持在相对脱水，透明的状态，与多个主动和被动系统的最佳光传输兼容。液体积聚是由控制液体进入和排出的过程之间的不平衡引起的，并且当内部或外部血视网膜屏障被破坏时，由Starling方程驱动。视网膜水离子体内稳态涉及多种复杂机制，本文综述了它们的分子和细胞基础，以及它们的失调如何导致视网膜水肿。通过分析人黄斑中连接蛋白和水通道的分布，提出了一些假设来解释为什么在黄斑区会特别形成水肿。详细介绍了可能由单一病因机制导致的黄斑水肿的“纯”临床表型。最后，作为复杂的多因素致病实例，对糖尿病性黄斑水肿进行了研究。对当前对黄斑水肿及其机制的了解的全面综述为识别这种威胁视力的疾病提供了新的预防和治疗策略。通过分析人黄斑中连接蛋白和水通道的分布，提出了一些假设来解释为什么在黄斑区会特别形成水肿。详细介绍了可能由单一病因机制导致的黄斑水肿的“纯”临床表型。最后，作为复杂的多因素致病实例，对糖尿病性黄斑水肿进行了研究。对当前对黄斑水肿及其机制的了解的全面综述为识别这种威胁视力的疾病提供了新的预防和治疗策略。通过分析人黄斑中连接蛋白和水通道的分布，提出了一些假设来解释为什么在黄斑区会特别形成水肿。详细介绍了可能由单一病因机制导致的黄斑水肿的“纯”临床表型。最后，作为复杂的多因素致病实例，对糖尿病性黄斑水肿进行了研究。对当前对黄斑水肿及其机制的了解的全面综述为识别这种威胁视力的疾病提供了新的预防和治疗策略。作为复杂的多因素致病实例，对糖尿病性黄斑水肿进行了研究。对当前对黄斑水肿及其机制的了解的全面综述为识别这种威胁视力的疾病提供了新的预防和治疗策略。作为复杂的多因素致病实例，对糖尿病性黄斑水肿进行了研究。对当前对黄斑水肿及其机制的了解的全面综述为识别这种威胁视力的疾病提供了新的预防和治疗策略。