Limbal stem cells: application in ocular biomedicine.

Corneal opacification due to limbal stem cell deficiency (LSCD) is an important cause for ocular morbidity, resulting from a number of intrinsic and extrinsic factors. While the extrinsic factors include conditions such as chemical or thermal injuries, intrinsic include dysfunction, or reduction in the number of stem cells either due to pathological changes in autoimmune diseases or secondary to certain clinical conditions such as diabetes, dry eye disorders, or multiple previous eye surgeries. LSCD is characterized by a classic triad of signs -- conjunctivalization, neovascularization and decrease in vision. With the increasing knowledge of limbal stem cells, the treatment of this condition has evolved from simple debridement to use of biological materials, direct transplantation of the healthy limbal tissue from the contralateral eye, or allogenic source to the use of cultivated limbal epithelial sheets. This chapter provides an update on the disease pathology, various treatment methodologies, with specific emphasis on the fast developing field of cell therapy and tissue engineering.