tRNA-derived small RNAs-Biogenesis, functions, and potential applications in ocular diseases: A review.

tRNA-derived small RNAs (tsRNAs), a burgeoning class of small non-coding RNAs, are emerging as pivotal regulators in gene expression and cellular signaling networks. Derived from specific cleavage of precursor or mature tRNAs, these molecules exhibit diverse functionalities, including epigenetic remodeling, transcriptional regulation, and translational modulation. Growing evidence underscores their significant roles in the pathogenesis of various ocular diseases, such as age-related macular degeneration, diabetic retinopathy, myopia, and cataract, where they influence critical processes like angiogenesis, inflammation, and neuronal homeostasis. Their dynamic expression profiles in ocular tissues and biofluids position tsRNAs as promising diagnostic biomarkers and therapeutic targets. This review systematically delineates the biogenesis and classification of tsRNAs, elaborates their multifaceted molecular mechanisms, and comprehensively examines their implications in ocular diseases. We further discuss the translational potential of tsRNAs in early detection and precision treatment of ocular diseases, while highlighting current challenges and future directions in this rapidly evolving field.