Wound healing patterns following perforation sustained during laser in situ keratomileusis

Background and purpose: Corneal perforation during laser in situ keratomile usis (LASIK) may interface with flap adhesion and wound healing. The purpos e of this study was to investigate wound healing patterns following corneal perforation sustained during LASIK in rabbits. Methods: Forty-two pigmented rabbit eyes underwent LASIK surgery, with 5.0- mm excimer laser treatment under the corneal nap, animals were divided into two groups: group I (n = 19) underwent the regular LASIK procedure with -1 0.0 D treatment, without perforation; in group II (n = 23), the cornea was perforated with the excimer laser. Treatment was discontinued once perforat ion was observed, and the corneal flap was replaced without sutures. Slit-l amp biomicroscopy, photography, and scatterometry were performed preoperati vely and at 1 and 2 days, 1 week, and weekly up to 1 month, 2 months, and 3 months postoperatively, Animals were killed at 1 day, 1 week, 1 month, and 3 months postoperatively and processed for light microscopic, electron mic roscopic, and immunohistochemical examinations. Results: In group I, the corneas remained clear throughout the experiment. In all eyes, the interface was not readily discernable clinically or histol ogically. Cornel wound healing was accompanied by minimal cell infiltration . Epithelial hyperplasia at the flap edge was noted at 1 week. Myofibroblas t activation was found at thr epithelial wedge where there was an epithelia l basement membrane break. In group II, the anterior chamber was shallow wi th no iris incarceration at the end of surgery. The corneas were clear (n = 6) ol showed mild to moderate edema (n = 12). Corneal edema peaked at 3.6 +/- 5.0 days and subsided thereafter. Corneal wounds healed similarly to th ose in group I except at the perforation site. The break in Descemet's memb rane and endothelium was covered with a fibrin plug on day 1, which resolve d thereafter 1. There was no statistically significant difference in the in cidence of postoperative infection (p = 1.0) or flap displacement (p = 0.69 ) rates between the two treatment groups. The scatterometry index peaked at 2 to 3 weeks postoperatively and was significantly higher in group II than in group I (p < 0.001). Conclusions: Although corneal perforation during LASIK surgery may interfer e with immediate postoperative flap adhesion, corneal wound healing followi ng LASIK perforation may be similar to that after an uncomplicated LASIK pr ocedure.