Keratocyte Loss and Repopulation of Anterior Corneal Stroma After De-epithelialization

Proliferation of the vascular endothelium of the iris following total debridement of the corneal epithelium and limbal excision of rabbits

“…This suggests that there was an initial stimulus for DNA replication, but not a significant renewal of the cells which took up 3 H-TdR during the first 2 days. Concerning the long-lasting labeling of vascular cells, it should be recalled that a similar event occurs with the keratocytes of the stroma, which after an initial and short stimulus for proliferation (epithelial damage) persist labeled for a long time [18,20]. In fact, this also occurred in our material, in which labeled keratocytes were observed from 2 to 21 days after 3 H-TdR injection in the experimental eyes, in paraffin sections of the cornea.…”

“…It must be recalled that the iris vascular reaction was widespread. We also observed keratocyte labeling throughout the cornea, a different condition from what has been previously reported for the debridement of only a small area on the central region of the cornea [18]. In this case, only the stroma The damage to the corneal epithelium also elicited a breakdown of the blood-aqueous barrier, as already reported under similar experimental conditions [12].…”

“…However, the reactions on the cornea are not restricted to the epithelium, since death and subsequent proliferation of keratocytes were also observed in the stroma adjacent to the epithelial damage [20]. The stimulus for keratocyte proliferation may last for a few days after the epithelial damage [18] whereas in control animals mitosis were rarely observed in the corneal stroma [5]. These changes caused by the epithelial wounding are attributed to the accelerated synthesis and liberation in the anterior eye segment of peptides which, among other properties, may stimulate proliferation of several cell types [8].…”

“…Even in the case when just a small portion of the centrally or the peripherally located corneal epithelium is gently scraped, it is already known that the reaction manifested by keratocyte death and proliferation seems to be restricted to the stroma underneath the epithelial damage [18]. In our preliminary experiments, it was verified that a partial epithelial scraping, with or without damage to the limbus, was enough to cause an increase in 3 H-TdR incorporation into the cells which make up the blood vessels of the iris, particularly the endothelial cells.…”

The Effect of Minoxidil on Keratocyte Proliferation in Cell Culture

“…The development of subepithelial haze that might cause a decrease in visual acuity and late regression of effect represents a potentially significant complication of excimer laser PRK [2][3][4]. Tissue ablation is followed by epithelial cell proliferation, keratocyte migration and proliferation with resultant collagen and ground substance production [5][6][7]. Although the mechanisms for the development of haze and the regression of effect are not entirely clear, it is proposed that subepithelial haze might be secondary to newly synthesized collagen fibers and other extracellular matrix components that are either biochemically or ultrastructurally different from normal [8][9][10][11][12].…”