Tear-Derived Exosomal miR-15a as New Diagnostic Tool for Diabetic Retinopathy

Diabetic retinopathy (DR) is a major complication of diabetes mellitus, affecting a significant percentage of the diabetic population. Early diagnosis and intervention are critical for preventing irreversible vision loss. Current diagnostic methods, although effective, have limitations. miRNA, a small non-coding RNA that inhibits the stability and/or translation of an mRNA by binding to the 3'-untranslated regions (3'-UTRs) of target mRNAs, has been increasingly recognized as being significantly associated with diabetes and can be obtained from tears. This study investigated the potential of tear fluid-derived exosomal miR-15a as a novel diagnostic marker for DR. Tear Samples were obtained from 135 diabetic patients (36 with diabetic retinopathy [DR] and 50 without DR) and 49 healthy controls. Exosomes were isolated, and the expression levels of exosomal miR-15a were measured using droplet digital PCR (ddPCR). The results showed that exosomal miR-15a expression was altered in diabetic and DR patients compared to healthy individuals. These findings indicate that exosomal miR-15a derived from tear fluid may play a role in the molecular mechanisms underlying diabetes and its complications. Furthermore, it holds potential as a non-invasive and reliable diagnostic biomarker for diabetic retinopathy, offering high sensitivity and specificity.