The detailed electron microscopic study of Campos et al1 in the Archives shows destruction of keratocytes in rabbit and monkey corneas after mechanical removal of the epithelium. They advise that some of the information presented in the article may be patented by the University of Southern California. I hope it is not the finding of the dead keratocytes. I suggest that removal of the epithelium the way it was done may not be as important as the trauma to remove it. Therefore, another control should have been done: a cornea traumatized as the test cornea, but without removing the epithelium. My comment is based on the fact that over 30 years ago investigators knew that mechanical trauma to the cornea could cause stroma and endothelial cell damage or destruction. Virginia Weimar, PhD, a fine investigator at Columbia University in New York, NY, had made these observations in the early