Keratoepithelioplasty in rat: development of a model and histological study

A model for keratoepithelioplasty (KEP) was developed using the Lewis rat, and histological studies were performed using this model. The entire corneal epithelium was removed mechanically and a 1.5-mm width of the conjunctiva including the limbus was excised. An oval corneal lamellar graft (3 x 1.5 mm) with an intact epithelium taken from another Lewis rat was transplanted on the denuded limbus. Biomicroscopic observations showed much less vascular invasion in the part of the cornea adjacent to the lenticule than in other parts of the cornea, and the cornea remained clear adjacent to the lenticule. Histologically, a few vessels were observed in the corneal stroma under the lenticule. Epithelial cells on the lenticule specimens showed histological characteristics of the corneal epithelium. These findings indicate that one of the functions of KEP is to block neovascularization in the newly developing corneal epithelium by transplanting the lenticule between the corneal epithelium and conjunctival vessels. The present study also confirmed that this model is useful in the research of the pathophysiological mechanism of KEP.