Corneal alkali burn in the rabbit. Waterbalance, healing and transparency.

Healing following a standardized central corneal alkali wound was studied morphologically in New Zealand white rabbits up to one year after the initial wound. Clinical examination, light and transmission electron microscopy was performed. The study was focused on how permanent scar tissue formed. Following the penetrating alkali injury, all cells (epithelium, keratocytes and endothelium) in the wound area disappeared. The fibroblasts/keratocytes repopulated an extensively swollen central corneal stroma. Cells and extracellular matrix filled stromal lacunae in an irregular fashion and upon deswelling the lacunae remained as irregularities in the stroma, reducing the transparency. In the periphery of the wound repopulation occurred in a less swollen stroma and normal cytoarchitecture and transparency resumed. It appears that the degree of swelling decides the degree of scar tissue formation in the corneal stroma following alkali wound healing.