Which cell type is the basic cell in the corneal stroma?

• A. Endothelial cell
• B. Keratocyte
• C. Epithelial cell
• D. Melanocyte

Answer: (B)

In the corneal stroma, the main cell responsible for maintaining the extracellular matrix and keeping the tissue transparent is the keratocyte. Keratocytes reside between the regularly arranged collagen lamellae and continuously synthesize collagen and proteoglycans that form the stroma’s supporting matrix. They are relatively quiet under normal conditions, which helps preserve the organized structure needed for transparency. If injury occurs, keratocytes can become fibroblasts or myofibroblasts to aid repair, but this can lead to scarring and loss of clarity if the response is excessive. Endothelial cells line the inner surface of the cornea and help regulate fluid balance, epithelial cells cover the outer corneal surface, and melanocytes are pigment cells not typically part of the corneal stroma, so they do not serve as the basic stroma cell.