Application and progress of swept source optical coherence tomography in choroid-related diseases

Central serous chorioretinopathy (CSC) is one of the choroidal spectrum diseases, characterized by choriod thickening and increased vascular permeability. Therefore it is very important to observe choroid, as this allows us to monitor it and formulate an appropriate therapeutic schedule. With the development of optical coherence tomography (OCT), our understanding of choroid has been significantly improved. We have got a deeper insight into its important role in posterior diseases, and also the diagnostic capability for choroidal and retinal diseases has also improved. In recent years, the development of swept source optical coherence tomography (SS-OCT) and swept source optical coherence tomography angiogrphy (SS-OCTA) has further advanced our ability to assess choroidal conditions. These technologies offer enhanced scanning wavelengths, depth, breadth, and scanning speed, enabling non-invasive quantitative assessment of choroidal structures. This has advanced our understanding of the pathophysiological mechanisms and clinical management of CSC and other choroidal spectrum diseases. This review summarizes the application of swept source optical coherence tomography (SS-OCT) and swept source optical coherence tomography angiography (SS-OCTA) in CSC and its research progress. The main advancements include: choroidal thickening in CSC is not limited to macular area, both choroidal vascular and stromal components are significantly increased; CSC can affect both eyes, although it often presents with unilateral symptoms; impaired vortex vein outflow plays a key role in the pathogenesis of this disease; SS-OCT can further monitor and analyze subretinal fluid accumulation in the posterior pole; differences in changes in choroidal parameters between acute and chronic CSC have been identified; and finally, the potential role of scleral mechanisms in this disease have been explored.