Advances in corneal preservation: A comparative narrative review of active and non-active methods.

Corneal transplantation, a critical treatment for corneal blindness, depends on effective preservation of donor corneal tissue. Preservation techniques are broadly classified into active and non-active methods based on the viability of endothelial cells. Active preservation-such as hypothermic storage and organ culture-maintains endothelial cell viability and is primarily used in penetrating keratoplasty. In contrast, non-active preservation methods, including glycerol storage and freeze-drying, maintain structural integrity without preserving viable cells, making them more suitable for lamellar keratoplasty. This review provides a comprehensive comparison of different corneal preservation strategies, summarizing their key characteristics, advantages, and recent advances. A better understanding of these methods may improve transplant outcomes and optimize the use of donated corneal tissue, thereby enhancing both the success rate and availability of corneal grafts.