The choroid is a key player in maintaining ocular homeostasis and plays a role in a variety of chorioretinal diseases, many of which are poorly understood. Recent advances in the field of single-cell RNA sequencing have yielded valuable insights into the properties of choroidal endothelial cells (CECs). Here, we review the role of the choroid in various physiological and pathophysiological mechanisms, focusing on the role of CECs. We also discuss new insights regarding the phenotypic properties of CECs, CEC subpopulations, and the value of measuring transcriptomics in primary CEC cultures derived from post-mortem eyes. In addition, we discuss key phenotypic, structural, and functional differences that distinguish CECs from other endothelial cells such as retinal vascular endothelial cells. Understanding the specific clinical and molecular properties of the choroid will shed new light on the pathogenesis of the broad clinical range of chorioretinal diseases such as age-related macular degeneration, central serous chorioretinopathy and other diseases within the pachychoroid spectrum, uveitis, and diabetic choroidopathy. Although our knowledge is still relatively limited with respect to the clinical features and molecular pathways that underlie these chorioretinal diseases, we summarise new approaches and discuss future directions for gaining new insights into these sight-threatening diseases and highlight new therapeutic strategies such as pluripotent stem cell‒based technologies and gene therapy.

脉络膜是维持眼内稳态的关键因素，并在多种脉络膜视网膜疾病中发挥作用，其中许多疾病知之甚少。单细胞 RNA 测序领域的最新进展对脉络膜内皮细胞 (CEC) 的特性产生了宝贵的见解。在这里，我们回顾了脉络膜在各种生理和病理生理机制中的作用，重点关注 CEC 的作用。我们还讨论了关于 CEC、CEC 亚群的表型特性的新见解，以及在源自死后眼睛的原代 CEC 培养物中测量转录组学的价值。此外，我们讨论了区分 CEC 与其他内皮细胞（如视网膜血管内皮细胞）的关键表型、结构和功能差异。了解脉络膜的特定临床和分子特性将为广泛临床范围的脉络膜视网膜疾病的发病机制提供新的线索，例如年龄相关性黄斑变性、中心性浆液性脉络膜视网膜病变和其他厚脉络膜疾病、葡萄膜炎和糖尿病性脉络膜病变。尽管我们对这些脉络膜视网膜疾病的临床特征和分子途径的了解仍然相对有限，但我们总结了新的方法并讨论了未来的方向，以获得对这些威胁视力的疾病的新见解，并强调新的治疗策略，如多能干细胞‒ 基于技术和基因治疗。