Purpose: To learn more about corneal wound healing after excimer laser photoablation.
Methods: Observations were made on the chronological changes in type I collagen, fibronectin, laminin, and type IV collagen after excimer ablation of rat cornea. Immunohistochemical techniques were used.
Results: There was no obvious change in the localization of type I collagen in the ablated area, but the localization of fibronectin, laminin, and type IV collagen changed remarkably. One day after ablation, immunofluorescent staining for fibronectin increased on the ablated surface. Subsequently, the fluorescence of fibronectin, laminin, and type IV collagen increased remarkably; in particular, the localization of these extracellular matrix proteins was sustained in the shallow layer of the stroma until about 24 weeks after ablation. Hematoxylin-eosin staining indicated that keratocytes temporarily disappeared 1 day after ablation, and activated keratocytes then migrated to the ablated areas.
Conclusions: These results suggest that activated keratocytes might be synthesizing the extracellular matrix components. Therefore sustained responses of keratocytes may be induced by excimer laser photoablation.