The choriocapillaris, a dense capillary network located at the posterior pole of the eye, is essential for supporting normal vision, supplying nutrients, and removing waste products from photoreceptor cells and the retinal pigment epithelium. The anatomical location, heterogeneity, and homeostatic interactions with surrounding cell types make the choroid complex to study both in vivo and in vitro. Recent advances in single-cell RNA sequencing, in vivo imaging, and in vitro cell modeling are vastly improving our knowledge of the choroid and its role in normal health and in age-related macular degeneration (AMD). Histologically, loss of endothelial cells (ECs) of the choriocapillaris occurs early in AMD concomitant with elevated formation of the membrane attack complex of complement. Advanced imaging has allowed us to visualize early choroidal blood flow changes in AMD in living patients, supporting histological findings of loss of choroidal ECs. Single-cell RNA sequencing is being used to characterize choroidal cell types transcriptionally and discover their altered patterns of gene expression in aging and disease. Advances in induced pluripotent stem cell protocols and 3D cultures will allow us to closely mimic the in vivo microenvironment of the choroid in vitro to better understand the mechanism leading to choriocapillaris loss in AMD.

中文翻译：

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脉络膜毛细血管在视觉中的重要作用：来自成像和分子生物学的新见解

脉络膜毛细血管是位于眼睛后极的致密毛细血管网络，对于支持正常视力、提供营养以及清除感光细胞和视网膜色素上皮中的废物至关重要。脉络膜的解剖位置、异质性以及与周围细胞类型的稳态相互作用使得脉络膜复合体可以在体内和体外进行研究。单细胞 RNA 测序、体内成像和体外细胞建模方面的最新进展极大地提高了我们对脉络膜及其在正常健康和年龄相关性黄斑变性 (AMD) 中的作用的认识。从组织学角度来看，AMD 早期就会发生脉络膜毛细血管内皮细胞 (EC) 的损失，同时伴随着补体膜攻击复合物形成的增加。先进的成像使我们能够观察活体患者 AMD 的早期脉络膜血流变化，支持脉络膜 EC 丢失的组织学发现。单细胞 RNA 测序可用于从转录角度表征脉络膜细胞类型，并发现其在衰老和疾病中基因表达模式的改变。诱导多能干细胞方案和 3D 培养的进展将使我们能够在体外密切模拟脉络膜的体内微环境，以更好地了解导致 AMD 中脉络膜毛细血管丢失的机制。