It has been shown that diabetic corneas manifest reduced rates of epithelial healing after denudement. Yet, in the diabetic patient, not only is the rate of corneal epithelial healing of clinical concern, abnormalities inherent in the diabetic corneal epithelial cytoarchitecture can cause substantial impediments to normal stromal healing. Histologically, diabetic corneas typically demonstrate thickening of the epithelial basal membrane (BM), decreased number of hemidesmosomes, and decreased number of nerve fiber endings. Studies of BM changes in diabetic corneas have yielded information regarding poor adhesion of the epithelial BM to the stroma. During vitrectomy in diabetic patients, when the cornea epithelium is removed, it separates as an intact sheet and the entire thickened BM, characteristic of diabetes, adheres to the epithelium. In contrast, when normal epithelium is removed by scraping, the BM remains adherent to the stroma.