In group 3,

treatment with dexamethasone was started on day 15 after the operation, when epithelial healing had been completed in some eyes, therefore, the combination therapy caused a partial non-significant acceleration of wound healing. However, it seemed that dexamethasone still prevented the acceleration effect of acetylcysteine on wound healing in those eyes, where the re-epithelialization of the epithelium was not completed. Since the changes in healing in groups 2 and 3 were Inhibitors,research,lifescience,medical not significant, more studies are needed to confirm these results. Ophthalmologic examinations showed that one month after the operations in group 1 corneal haze of treated eyes was Inhibitors,research,lifescience,medical greater than that in the control eyes. By contrast, it was less in treated eyes than in the control eyes in group 2 and 3. Although not significant, two and three months after the operation in all groups, corneal haze in treated eyes of groups 1, 2, or 3 was less than that in respective controls. These results show that using dexamethasone immediately after corneal ulceration can delay wound healing and increase corneal haze. Inhibitors,research,lifescience,medical However, when dexamethasone is used after the completion the epithelial defect or a few days later, it cannot delay wound healing and may decrease corneal haze. The use of local corticosteroids in the management of corneal wound healing

is controversial.11-16,34-39 Some investigators have reported that dexamethasone have some beneficial effects on corneal wound healing.11-16 On the contrary, others have shown that corticosteroids, including dexamethasone, are associated with an unacceptably high incidence of unwanted side effects.34-39 Francois

and Feher reported that Decitabine corticosteroid treatment was harmful during a critical period Inhibitors,research,lifescience,medical of two to three weeks after the burn, because steroids could retard the fibroblastic repopulation of the acellular stroma during this period.37 Such a retardation decreases the synthesis of new collagen in the wound, and results in more severe corneal ulceration. After such a period, the repopulation of fibroblasts Inhibitors,research,lifescience,medical occurs in the stroma, and stromal matrix materials are properly secreted. Therefore, corticosteroid treatment is less harmful. Kim et al. showed that an increase in the number of keratocytes and degree of apoptosis could increase the corneal gaze.10 Epithelial defects are known to induce Annual Review of Pharmacology and Toxicology keratocyte apoptosis and an inflammatory cell response, producing alterations in the extracellular stromal matrix composition that are directly proportional to the healing time of the epithelial defects. 9 Faster epithelial healing induces less keratocyte apoptosis and inflammatory cell infiltration, and reduces the upregulation of chondroitin sulfate in the corneal stroma adjacent to the epithelial defect. Minimizing stromal changes by inducing faster epithelial healing can improve the refractive outcomes.