The therapeutic potential of bone marrow mesenchymal stem cells-derived exosomes for retinal and optic nerve diseases.

Bone marrow mesenchymal stem cell-derived exosomes (BMSC-exos) represent a promising cell-free therapeutic strategy that offers significant advantages over cell transplantation in the treatment of retinal and optic nerve diseases. By mediating intercellular communication, these nanovesicles deliver bioactive cargo (miRNAs, proteins, lipids) that target key pathological processes such as neuroinflammation, neuronal apoptosis, vascular dysfunction, and oxidative stress. This review aims to systematically summarize current knowledge on and critically evaluate the therapeutic potential of BMSC-exos for major retinal diseases (e.g., diabetic retinopathy, retinal degeneration, and retinal ischaemia) and optic nerve disorders (e.g., glaucoma and optic nerve injury). We review the biogenesis, cargo composition (especially key neuroprotective factors such as miR-21 and miR-146a), and intercellular communication mechanisms of BMSC-exos. Furthermore, we synthesize evidence describing their multifaceted therapeutic effects-including potent neuroprotective, anti-inflammatory, antiapoptotic, and proangiogenic activities-from in vitro and in vivo studies across relevant disease models. Crucially, we also discuss the substantial barriers impeding translation, including the intrinsic heterogeneity of exosome preparations which complicates standardization, and the notable absence of active interventional clinical trials for retinal indications due to insufficient long-term safety data. Overall, this review highlights the transformative potential of BMSC-exos for improving visual outcomes, while emphasizing that clinical realization is contingent upon overcoming these critical translational hurdles.