In a study of 141 cases in different stages of trachoma, a definite change was observed in the curvature of upper part of cornea, which had become ectatic. The difference in curvature depended on the stage and severity of the trachoma. Most of the patients had fourth stage trachoma. Also, the degree of ectasia was greatest in the late stages of the disease--a point that must be kept in mind when lamellar keratoplasty is done in this type of case.