Laser in situ keratomileusis flap margin: Wound healing and complications imaged by in vivo confocal microscopy

PURPOSE: To examine the healing response of laser in situ keratomileusis fl ap margin in vivo. METHODS: Forty-three eyes of 43 patients who had undergone myopic (n = 39) or hyperopic (n = 4) laser in situ keratomileusis were examined once after surgery. The flap margin was imaged by in vivo confocal microscopy at vario us depths, and the wound healing response, flap alignment, and complication s were evaluated. Ten eyes were examined on day 3 postoperatively, 13 eyes at 1 to 2 weeks, 10 eyes at 1 to 2 months, five eyes at 3 months, and five eyes at 6 months or later. RESULTS: At 3 days after laser in situ keratomileusis, the surface epitheli um and basal epithelium appeared normal. Keratocyte activation was stronges t at 1 to 2 weeks and 1 to 2 months, and an increased amount of haze was ob served correspondingly. Intrastromal epithelial cells forming a plug could occasionally be perceived in the wound gape. Wound constriction was complet ed in most cases by 3 to 6 months or later. Good alignment was observed in 12 of 4 3 flaps (27.9%) and moderate and poor alignment in 17 of 43 flaps ( 39.5%) and 13 of 43 flaps (30.2%), respectively. Poor alignment was not ass ociated with lamellar epithelial ingrowth. Epithelial ingrowth was associat ed with dense haze at the interface. Diffuse lamellar keratitis was imaged in two corneas after hyperopic laser in situ keratomileusis. CONCLUSIONS: The laser in situ keratomileusis incision wound at the flap ma rgin appears to heal after the sequence observed in incisional wounds in no nhuman primates. Complications, such as lamellar epithelial in growth and d iffuse lamellar keratitis, were often observed, particularly after hyperopi c laser in situ keratomileusis. (C) 2000 by Elsevier Science Inc. All right s reserved.