Keratocytes, stromal

There is a parallel to draw between the Thill and assistant study and the study by Kubota and Fagerlhom [15] who have demonstrated that the importance of the initial corneal edema, resulting from a bum, is correlated to the importance of the sequelar cicatricial leukoma that causes the drop of vision. The stromal lacunae, fonned by the edema, will be colonized by the keratocytes. After the resorption of the edema and at the level of these lacunae, the keratocytes form a zone of cicatricial tissue, which is the origin of the leukoma. These keratocytes also produce an unorganized network of collagen fibrillae, thus causing the drop of transparency of the cornea. 

FIGURE 39.1. The three cell layers of the cornea. Shown on the left is a frozen section of an adult rabbit cornea stained with hematoxylin and eosin. On the right is a frozen section of a 6 week old mouse cornea. The mouse cornea is not fully mature until 8 weeks after birth. The left half visualizes the cornea by phase contrast microscopy. The right half shows the nuclei by DAPI staining. The density of the cells in the epithelial layer, and the paucity of keratocytes in the stromal layer are clearly seen with the nuclear stain. 

The stroma constitutes approximately 90% of the total corneal thickness and is primarily composed of collagen fibers, keratocytes, and glycosaminoglycans. The imiform arrangement of the collagen fibers is the major determinant of corneal transparency, in contrast to the opaque and less regularly arranged fibers of the sclera. Disruption of the stromal layer regularity results in loss of corneal transparency and potential scar formation. 

While pain after photorefractive keratectomy needs to be treated effectively, the non-prescribed long-term misuse of local anesthetics can lead to impaired wound healing. Postulated mechanisms include inhibition of corneal epithelial migration and adhesion and toxic effects on stromal keratocytes [49 , 50 ]. 

West-Mays, J.A., Dwivedi, D.J., 2006. The keratocyte corneal stromal cell with variable repair phenotypes. Int. J. Biochem. Cell Biol. 38 (10), 1625-1631. 

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