Usui Yoshihiko
Department of Ophthalmology, Tokyo Medical University, Tokyo, Japan.
JMA J. 2020 Jul 15;3(3):201-207. doi: 10.31662/jmaj.2020-0022. Epub 2020 Jul 7.
The retina transmits light signals to the brain via a complex structure composed of photoreceptor cells, neurons including ganglion cells, glial cells such as astrocytes and Mueller cells, as well as retinal blood vessels that feed the retina. The retina performs such high-level physiological function and maintains homeostasis effectively through interactions among the cells that form the neurovascular units (NVUs). Furthermore, as a component of the blood‒retinal barrier (BRB), the vascular structure of the retina is functionally based on the NVUs, in which the nervous system and the vascular tissues collaborate in a mutually supportive relationship. Retinal neurons such as ganglion cells and amacrine cells are traditionally considered to be involved only in visual function, but multiple functionality of neurons attracted attention lately, and retinal neurons play an important role in the formation and function of retinal blood vessels. In other words, damage to neurons indirectly affects retinal blood vessels. Diabetic macular edema is the leading cause of vision loss in diabetic retinopathy, and this type of edema results in neurological and vascular disorders. In this article, the regulatory mechanism of retinal capillaries in diabetic macular edema is reviewed from the viewpoint of NVU.
视网膜通过一个复杂的结构将光信号传输至大脑，该结构由光感受器细胞、包括神经节细胞在内的神经元、如星形胶质细胞和米勒细胞的胶质细胞以及为视网膜供血的视网膜血管组成。视网膜通过形成神经血管单元（NVU）的细胞间相互作用，执行如此高级别的生理功能并有效维持体内平衡。此外，作为血视网膜屏障（BRB）的一个组成部分，视网膜的血管结构在功能上基于NVU，其中神经系统和血管组织以相互支持的关系协作。传统上认为视网膜神经元如神经节细胞和无长突细胞仅参与视觉功能，但神经元的多种功能最近引起了关注，并且视网膜神经元在视网膜血管的形成和功能中发挥重要作用。换句话说，神经元损伤会间接影响视网膜血管。糖尿病性黄斑水肿是糖尿病视网膜病变中视力丧失的主要原因，并且这种类型的水肿会导致神经和血管紊乱。在本文中，从NVU的角度综述了糖尿病性黄斑水肿中视网膜毛细血管的调节机制。
