Limbal stem cell transplantation: new progresses and challenges.

Patients with limbal stem cell deficiency (LSCD) suffer from photophobia and a severe loss of vision uncorrectable by conventional PKP. This literature review shows that new strategies can be formulated for treating LSCD. Early cryopreserved amniotic membrane transplantation (AMT) as a temporary biological bandage with sutures or with sutureless ProKera in the acute stage of chemical burn and Stevens-Johnson syndrome prevents the occurrence of LSCD by preserving and expanding the remaining limbal epithelial stem cells. Similarly, remaining limbal stem cells can also be expanded in corneal surfaces with partial or nearly total LSCD if corneal pannus is removed and AMT is performed as a graft with or without sutures by the use of fibrin glue. Moreover, AMT as a temporary bandage and a graft using fibrin glue can also facilitate corneal surface reconstruction by reducing the size of a conjunctival limbal autograft (CLAU) to one 60 degrees graft for unilateral total LSCD as well as promote the success of a keratolimbal allograft (KLAL) for bilateral total LSCD. The latter success is further dictated by effective systemic immunosuppression and by measures to restore the ocular surface defenses, suppress conjunctival inflammation, and correct cicatricial complications so that a stable tear film can be maintained before surgery. This review also summarizes recent findings and outlines future challenges that we need to overcome in squamous metaplasia, that is, another major type of ocular surface failure.