Abstract:Exosomes, which are 30-200nm nano-sized vesicles, can be released by many cell types into the extracellular environment. Various biological active substances have been identified in the exosomal lumen, including proteins, mRNA, and microRNA(miRNA). miRNA is small non-coding RNA involved in post-transcriptional generegulation, participating in many biological activities. They can be selectively packed into exosomes, delivered to neighboring or distant cells, and regulate the functions of recipient cells. Accumulating evidence showed that exosome-derived miRNA play important roles in initiation, progression, and prognosis of diverse ocular diseases. Thus, exosome-derived miRNA are considered as potential biomarkers for diagnosis and prognosis. This review summarizes the basic characteristics of exosome-derived miRNA and their research progresses in different ocular diseases.