Update on limbal stem cell transplantation.

Limbal epithelial stem cells are the primary source of corneal epithelial cell regeneration. Limbal stem cell deficiency (LSCD) can develop in traumatic, immunologic, or genetic diseases that affect the ocular surface. LSCD leads to conjunctivalization, with corneal vascularization and opacification and subsequent loss of vision. Limbal stem cell transplantation is a surgical treatment to address LSCD and restore a corneal epithelial phenotype. Based on the source of cells, limbal transplant can be autologous or allogenic. Many surgical techniques are defined according to the source of the stem cells and the carrier tissues that are used. More recently, ex vivo expanded bioengineered epithelial cells have been used to reconstruct the corneal surface using autologous cells to eliminate the risk of rejection. Before transplantation, a systematic exam of the lids, eyelashes, fornices, and aqueous tears is mandatory and every effort should be made to optimize ocular surface health and control inflammation to enhance the chances of graft survival. Postoperative care is also another major determinant of success. Any factor that destabilizes the ocular surface needs to be addressed. In addition, systemic and topical immunosuppressants are also needed in all allograft recipients. In addition to pre-operative and postoperative care and the surgery itself, the etiology of LSCD also has an impact on the outcome. The prognosis of inflammatory diseases such as Stevens-Johnson syndrome is the worst among disorders causing LSCD.