**7. Conclusion and perspective**

Corneal transplantation is the only widely accepted treatment for corneal blindness. However, the shortfall of high-quality donor cornea worldwide has made it very challenging. Several approaches have been explored to replace donor corneas, ranging from incorporation of stem cells and decellularized extracellular matrix scaffold to cell-free approaches. Cell-free biomaterial approaches have shown promising potential in promoting in situ corneal regeneration without aggravating the risk of rejection. In-situ gelation of biomaterials opens a new path in corneal regeneration as it does not require extensive surgical intervention, and could reduce the risk of infection, scar formation, and patient discomfort. However, this technique is ineffective in patients with depleted stem or progenitor cells.

More research focusing on developing of biomaterials for high-risk patients is needed. Exosomes derived from cells have recently shown potential in early diagnosis and capabilities to modulate pathological disease state. Future studies should focus on understanding the role of exosomes in corneal pathologies and combining biomaterials with exosomes to explore the additive effect of both strategies.

Finally, it is essential to consider regulatory pathway beforehand while designing and developing corneal implants for clinical applications for effective translation from bench-to-bench side.
