Retinal vein occlusion (RVO) is a serious retinal vascular disease, often accompanied by systemic cardiovascular and cerebrovascular diseases, with ocular changes such as macular oedema, retinal ischemia, and even neovascularisation formation, which, as a common slow disease of the fundus, seriously affects people's vision and quality of life. With the development of optical coherence tomography, the research on the role of the choroid in RVO's onset and progression has gradually attracted people's attention. Currently, observational metrics for changes in the choroidal layer of the RVO eyes have expanded from two-dimensional thickness to three-dimensional parameters such as volume, blood flow density, and blood flow velocity. Some studies have also incorporated artificial intelligence algorithm technologies. In the future, there remains a need to further enrich data on the choroidal layer of the fundus of the RVO eyes to enhance comprehensive understanding of RVO, providing new insights for its clinical prevention and treatment.