Effect of Corneal Epithelial Flap on the corneal wound healing of canine eyes

ABSTRACT

PURPOSE: LASEK is a newly developed refractive surgery technique that can make up for the complications from PRK and LASIK. The most unique procedures in LASEK is covering of the cornea with epithelial flap after keratectomy. We examined the effect of corneal epithelial flap on the wound healing of canine cornea. METHODS: Operation was performed in eyes from 12 dogs, and the 12 eyes were recovered with epithelial flap and the remaining 12 eyes were recovered without epithelial flap. Wound healing process was compared using fluorescein staining, light and transmission electron microscopic examination. RESULTS: Fluorescein stained area of the cornea was reduced with time in both groups, and from 9 hours after the operation, it was significantly reduced in the group with epithelial flap compared with those of the group without epithelial flap (p< 0.05). On light microscopic examination of the group with epithelial flap, and normal epithelial structure was found at 24 and 48 hours, respectively. However, in the group without epithelial flap, no complete reepithelialization had occurred on center at 48 hours after the operation. On transmission electron microscopic examination, eyes of the group with epithelial flap showed hemidesmosomes in the area where epithelial flap was closely contacted with the stroma at 24 hours, and they were completely developed at 48 hours. On the other hand, in the group without epithelial flap, hemidesmosomes developed only in the proximal portion but not at the leading edge even at 48 hours. CONCLUSIONS: These results suggest that corneal epithelial flap accelerate the wound healing process of the cornea and the wound healing process depend on the vitality of the epithelial flap.