目前糖尿病视功能损伤研究集中于视网膜微血管病变，但很多患者视功能下降用此无法解释。脉络膜血管支持视网膜外层光感受器细胞的营养和代谢，其异常导致的光感受器细胞损伤在视功能下降中占有不可忽略的地位，研究表明脉络膜血流主要由自主神经调节，而糖尿病自主神经病变发生早，且累及全身多个器官。目前糖尿病脉络膜循环的自主神经调节通路异常及机制研究少见报导，我们前期研究中发现糖尿病模型鼠控制脉络膜循环的自主神经通路中：脊髓胸1段，脑室旁核等出现了形态异常。因此提出假设：糖尿病脉络膜自主神经通路异常在视功能损害中起重要作用。本项目拟通过功能磁共振技术探索糖尿病患者自主神经通路功能连接以及神经递质改变。构建糖尿病动物模型，联合神经示踪、电刺激毁损及免疫组化、分生技术探寻糖尿病脉络膜血流自主神经调控通路异常的物质基础。以期从另一视角认识糖尿病视功能损害的发生，发展机制并为临床治疗新靶点提供依据。

Diabetic visual function impairment is the leading cause of blindness in the people of working age. By far most DR studies focus on retinal vascular impairment. However, in many patients visial function impairment occurs before the retinal vascular damage and the reason is still vague. The blood supply of the outer layer of the retina (includes the photoreceptor cells) and macular comes from the choroidal vessel. Choroidal circulatory plays a key role in maintaining the function of retinal photoreceptors and macular. Previous studies have demonstrated that choroidal blood flow（ChBF） was innervated and controlled by autonomic nervous system(ANS). Furthermore there is high prevalence of diabetic automtic neuropathy (DAN) in patients with diabetes mellitus(DM).Using intrachoroidal injection of the transneuronal retrograde tracer pseudorabies virus (PRV), we previously found the deficit of ANS pathway in diabetic rats. Therefore, this project raises a presumption: automatic nervous system pathway may play a key role in the control of choroidal blood flow and the pathogenesis of DR. The project will make use of multi- modal functional MRI techniques to explore the functional connections, fiber connections and neurotransmitter variation in the autonomic nervous pathway among patients with DR in different stage. While building an animal model of diabetes mellitus，DM) in rats through electrophysiological technologies, as well as nerve tracing and immunohistochemical methods , this project will verify further the transmission way and the biochemical bases of choroidal blood flow signal. We hope to clarify the regulation mechanism of choroidal blood flow in autonomic nervous pathways and to provide a knock-down evidence for the therapy in the future.