Electrosurgical keratoplasty. Clinicopathologic correlation.

A patient with keratoconus who could not tolerate a contact lens underwent electrosurgical keratoplasty. Postoperatively, the central cornea was markedly flattened, but five weeks later the central steepening had recurred. Six months after the procedure, a penetrating keratoplasty was performed. Pathologic examination of the corneal button revealed an intact epithelium and basement membrane. Bowman's membrane was completely destroyed in the treated areas. Stromal scarring extended to involve the anterior two thirds of the corneal stroma. The collagen in this area was contracted and folded. The keratocytes and stromal collagen of the posterior third of the cornea were normal by light microscopy. Descemet's membrane and the endothelium also were normal. Despite the short-lived flattening of corneal topography, this procedure dramatically altered the stromal collagen in the anterior two thirds of the cornea.