Limbal epithelial stem cells are responsible for renewal of the corneal epithelium. When these cells become dysfunctional or deficient, a disease called limbal stem cell deficiency (LSCD) develops which causes visual impairment and reduced quality of life. LSCD afflicts thousands of patients in North America. In patients with unilateral LSCD, limbal stem cells from the healthy fellow eye can be used for corneal surface reconstruction in a procedure called conjunctival limbal autograft (CLAU). Although CLAU is successful in majority of cases with unilateral LSCD, it carries the potential risk of causing LSCD in the donor cornea as two large pieces of the limbus are conventionally harvested for the procedure. To circumvent this risk, a new technique has recently been developed, so-called Cultivated Autologous Limbal Epithelial Cell (CALEC) transplantation. In this technique, cells from a small area of the donor limbus are expanded in the laboratory before transplantation to the diseased eye, minimizing the risk of damage to the donor cornea. As there is no CALEC product available in the U.S., we have optimized and standardized the techniques of CALEC preparation by removing antibiotics and murine feeder cells, and employing highly reproducible methods for cell isolation, expansion and quality control of the resultant CALEC sheets. We have received Investigational New Drug Application (IND #16102) approval from the FDA for our CALEC graft to perform a clinical trial at the Massachusetts Eye and Ear Infirmary (MEEI), Boston, MA, for unilateral LSCD. This is a single center study to assess safety and feasibility of CALEC grafts and to compare its efficacy to CLAU in 24 patients with unilateral LSCD. Study design has been approved by the FDA. By showing the safety, feasibility and efficacy of CALEC, this study will pave the way for widespread use of the CALEC transplantation in patients with unilateral LSCD by sharing the technology with other institutions across the U.S. This is a resubmission of a previously submitted U-10 grant. There are three companion UG-1 Cooperative Agreements including Chair?s Grant, Coordinating Center Grant, and Resource Center Grant. In the Chair?s Grant, Ula Jurkunas, MD, and Ahmad Kheirkhah, MD are the Principal Investigators who will be responsible for the overall conduct of this study and for providing scientific, technical, and administrative leadership. MEEI will be the Clinical Center which will be responsible for recruitment and retention of the study participants and implementation of the study protocol. Coordinating Center Grant will be submitted by Jaeb Center for Health Research, Tampa, FL, which will provide the scientific, statistical and methodological leadership, logistical coordination and support for the study. Resource Center Grant will be submitted by Connell and O?Reilly Families Cell Manipulation Core Facility (CMCF) at the Dana-Farber Cancer Institute, Boston, MA, which will manufacture the CALEC graft. An NEI Program Officer will be involved for these Cooperative Agreements to assist the Principal Investigators in all aspects of the study.