Abstract: Exosomes are small vesicles secreted into the extracellular cells after the fusion of intracellular polycystic bodies and cytoplasmic membranes. Exosomes contain a variety of active substances, and their roles in intercellular communication, disease progression or as biomarkers have been gradually concerned by researchers of fundus diseases. Studies have shown that exosome is involved in the pathological process of wet age-related macular degeneration (wAMD), while mesenchymal stem cell exosomes reduce the transcription and translation of vascular endothelial growth factor (VEGF) in wAMD. In rat diabetic retinopathy, IgG-containing exosomes in plasma activate the classical complement pathway in the retina to promote endothelial injury; while mesenchymal stem cell derived exosomes containing miR-126 can limit endothelial cell injury. In ischemic retinopathy, exosomes of bone marrow mesenchymal stem cells restore retinal function in ischemic mice. Studies on patients with macular hole showed that mesenchymal stem cell exosomes isolated from human umbilical cord tissue combined with vitrectomy had therapeutic effect on macular hole. Exosomes secreted by mesenchymal stem cells in patients with retinal detachment can inhibit the apoptosis of photoreceptor cells. Detection of exosome markers in patients with uveal melanoma is expected to be an early diagnosis method for uveal melanoma. Exosomes secreted by microglia have protective effect on retinoprthy of prematurity. With the understanding of exosome system and its related signal transmission mechanism and disease outcome process in fundus diseases, it is of great significance to optimize treatment and prevention of fundus diseases. (Int Rev Ophthalmol, 2020, 45：442-448)

Key words: exosomes, fundus disease, mesenchymal stem cell