Introduction: The corneal epithelium is a fast regenerating , protective shield, maintained by the proliferation of stem cells, located in the limbus. In cases of compromised ocular surface due to chemical burns, severe trauma injury, Stevens-Johnson syndrome , HSV infection, radiation keratopathy, or contact lens induced keratopathy, the limbal stem cell activity reduces to a different degree. Eyes with a limbal stem cell deficiency produce inefficient epithelium, which ultimately leads to decreased vision and comfort due to corneal irregularity. Treatment for these conditions has become more advanced recently by utilising limbal stem cell transplantation techniques, using allo- or autotransplants.
Materials and Methods: Review of literature and clinical cases reveal several strategies for treatment, including keratolimbal allograft transplantation, cultured limbal epithelial transplantation and autologous limbal epithelial transplantation. In cases of bilateral total stem cell deficiency, a keratolimbal graft is obtained from a corneal bank, and transplanted onto the recipient eye. Living relative might also be used as a donor but with caution. When the deficiency is unilateral, the healthy eye of the patient may serve as a source of autologous limbal stem cells. After a small biopsy, the cells are either cultivated in a laboratory before transplantation, or directly `seeded` onto the damaged eye surface using an amniotic membrane as a vehicle.
Results: The primary measure of success in a treatment of limbal stem cell deficiency is the clinical presence of a stable ocular surface epithelium with no superficial corneal vascularization. Due to the high risk of immune rejection, treatment with an allograft offers poor long-term outcome when compared with the autograft transplantation. Several studies have proven the cultivated limbal epithelial transplantation to be a procedure with a success rate over 72%. One clinical trial on the autologous limbal epithelial transplantation demonstrates that at a median postoperative follow-up of 1.5 years (range, 1-4 years), 95 out of 125 eyes maintained a successful outcome. The main reasons for failure were acid injuries and severe symblepharon.
Conclusion: Cultivated limbal epithelial transplantation and autologous limbal epithelial transplantation are reliable techniques for long-lasting corneal reconstruction and vision restoration in unilateral limbal stem cell deficiency. Autologous limbal epithelial transplantation is probably preferable particularly where cell cultivation facilities are unavailable.
