中心性浆液性视网膜脉络膜病变(CSC)是常见的眼底病之一，目前认为它的发病与脉络膜循环障碍有关，但具体机制尚不明确。近年来，光动力疗法(PDT)能改善脉络膜循环，促使神经上皮下积液快速吸收,减少复发率，成为CSC公认的治疗方法。然而，PDT治疗CSC的参数，如光流量、光敏剂的剂量（全剂量/半剂量），尚存在争议。扫频光相干断层技术(SS-OCT)因近期相关技术的改进，使其穿透性较频域OCT大大提高，能分辨脉络膜细节。本项目拟利用SS-OCT观察CSC后极部脉络膜的厚度分布，分析其与视网膜色素上皮病变位置的关系，加深对CSC病理机制的认识；在视力及OCT监测下，观察脉络膜厚度随病程的变化，加深对CSC病理过程中脉络膜变化的认识；建立CSC的动物模型，引入不同参数PDT治疗，比较不同参数PDT对于脉络膜厚度的治疗效果差异，并探索不同参数PDT对于视网膜的可能毒性，为PDT参数的优化提供依据。

Central serous chorioretinopathy (CSC) is a common macular disease, which is considered to be caused by hyperpermeability of the choroid. However, the mechanism remains unclear. Photodynamic therapy(PDT), usually leading to resolution of sub-retinal fluid and reduction of recurrent rate, has become the standard care for persistent sub-retinal fluid in CSC. However, the parameter of PDT for CSC remains controversial. With the advent of swept source optical coherence tomography (SS-OCT), it is now possible to obtain high-resolution.cross-sectional images of the choroid in a noninvasive manner, and thus, to characterize many forms of choroidal pathologic features. In the current study, we try to use SS-OCT to picture the choroid thickness map within the posterior pole and figure out its relation with retinal pigment epithelial abnormalities, and to explore the time-periodic changes of choroid thickness at the posterior pole. Moreover, we try to set an animal model of CSC and then compare the difference in choroid thickness change and the possible toxicity to retina due to different.parameters of PDT, and thus to help to optimize PDT parameters.