Ocular Surface Reconstruction With Tissue–Engineered Epithelial Cell Sheets Comprising Autologous Oral Mucosal Epithelium in Patients With Ocular Cicatricial Pemphigoid

Abstract

Abstract: : Purpose: Advanced ocular cicatricial pemphigoid (OCP) is one of the major causes of bilateral total limbal stem cell deficiencies. It can be treated with allogeneic corneal epithelial transplantation, but graft failure is common due to epithelial rejection. To avoid epithelial rejection, we reported an alternative replacement strategy for damaged corneal epithelium involving a tissue–engineered epithelial cell sheet comprising autologous oral mucosal epithelium in rabbits (ARVO 2002). In this study, we applied this approach to OCP patients. Methods: The subjects were 4 eyes of 3 OCP patients with bilateral total limbal stem cell deficiencies. We harvested 3X3 mm–specimens of oral mucosal tissue and obtained epithelial cell suspension. Colony–forming assay was performed to assess the stem or progenitor cell population in this cell suspension. Tissue–engineered epithelial cell sheets were fabricated ex vivo by culturing harvested cells on temperature–responsive cell culture surfaces with mitomycin C–treated 3T3 feeder cells for two weeks. After surgically removing conjunctival fibrovascular tissues from corneal sites, cultured autologous cell sheets harvested using a simple reduced–temperature treatment were transplanted directly to the patients’ denuded corneal surfaces without sutures. Postoperatively, therapeutic contact lenses were used during a mean follow–up of 17 months. Results:Oral mucosal epithelial cell sheets as well as corneal epithelial cell sheets cultured under these culture conditions highly resemble in vivo corneal epithelium with similar optical transparency. Colony–forming efficiency representing stem or progenitor cell population for harvested patient’s tissues was 1.2 ± 0.2 percent (mean ± SE). The tissue–engineered epithelial cell sheets readily adhered to the corneal stroma as did the corneal epithelial cell sheets. Complete re–epithelialization of patients’ corneal surfaces occurred within one week in all four eyes. Corneal transparency was restored within one month after surgery, and final visual acuity improved in all eyes. Conclusions: Tissue–engineered epithelial cell sheets fabricated ex vivo from autologous oral mucosal epithelial cells are effective for reconstructing the corneal surface and restoring vision in OCP patients.

Keywords: cornea: epithelium • transplantation • keratoprostheses