Corneal Endothelial Tissue Bioengineering Using Cultured Human Corneal Endothelial Precursor Cells

The cornea is composed of a multilayered epithelium, Bowman's membrane, stroma, Descemet's membrane, and endothelium. The corneal endothelium (CE) is a single layer of hexagonal cells that separates the corneal stroma from the aqueous humor of the anterior chamber. Transparency of the cornea is maintained by regulation of stromal hydration through the barrier and pump functions of the CE, and corneal transplantation has long been used to treat corneal endothelial defects. In fact, more than half of the patients who undergo full-thickness corneal transplantation have impairment of visual acuity due to corneal endothelial problems alone and have a normal corneal epithelium (Cosar et al., 2002; Mannis et al., 1981; Rapuano et al., 1990). Corneal transplantation requires a fresh human cornea, but there is a worldwide shortage of donors (Barboza et al., 2007; Cao et al., 2006; Shimazaki et al., 2004; Tuppin et al., 2007).