Effect of steroids and nonsteroidal anti-inflammatory agents on stromal wound healing following excimer laser keratectomy in rabbits.

BACKGROUND AND OBJECTIVE: The effect of topical corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs) on stromal wound healing after excimer laser keratectomy was evaluated quantitatively.

MATERIALS AND METHODS: Excimer laser keratectomy was performed in each eye of 75 rabbits and the animals were divided into five groups according to planned post-operative medications: group I, 0.1% dexamethasone; group II, 0.1% fluorometholone; group III, 0.03% flurbiprofen; group IV, 0.1% dexamethasone and 0.03% flurbiprofen; and control group V, balanced salt solution. All treatment regimens were instilled four times daily. After dichlorotriazinyl aminofluorescein (DTAF) or hematoxylin-eosin staining, the thickness of new collagen and keratocyte density were quantified by image analysis system. In addition, the ultrastructural alterations in stroma were examined by transmission electron microscopy.

RESULTS: At four weeks, keratocyte density had peaked and new collagen identified in all groups. At 12 weeks, new collagen thickness and keratocyte density of the control were significantly different from that of each experimental group (P < 0.05). Transmission electron microscopy showed the activated keratocytes and extracellular matrixes deposition. At 12 weeks, the structural changes had much subsided in each experimental group but sustained in control.

CONCLUSION: Topically applied corticosteroids and NSAIDs can modulate stromal wound healing after excimer laser keratectomy and the effect of dexamethasone, which can be evaluated by the quantitative analysis of the morphologic changes, is the most prominent.