In a series of 30 vitrectomy patients, postoperative corneal complications developed in 14 (47%). Thirteen (92%) of the 14 patients with complications were diabetic. Other factors that were positively correlated with the development of corneal complications included decreased corneal sensitivity, intraoperative lensectomy, and intraoperative epithelial debridement. The corneal complications involved the epithelium in 11 (78%) of the 14 complicated cases, with involvement of the endothelium (as manifested by stromal edema) in five (35%) cases. The diabetic human corneal epithelium contains considerable levels of sorbitol and fructose, which indicates the probable presence of the sorbitol pathway. As in the lens, this pathway may lead to osmotic changes that make the diabetic corneal epithelium more vulnerable to damage intraoperatively. Postoperatively, reepithelialization is delayed because of a probable failure of adhesion of cells to the underlying basement membrane.