A compilation of three histolopathologic studies of corneal graft specimens shows that approximately 50% of opaque grafts have retrocorneal membranes, ie, connective tissue extending from the wound behind the Descemet's membrane.1-3 This postoperative complication of keratoplasty was first described in 1901 by Fuchs, who felt that iritis was the factor responsible for its development.4 Since this report by Fuchs, there have been numerous statements in the literature as to the cause of this so-called retrocorneal membrane (Table).5-11 The great majority was based on clinical observations or histologic examinations after the development of the complication. Laboratory investigations aimed specifically at determining the cause and development of the retrocorneal membrane are few. In 1957, Leigh8 mentioned that a retrocorneal membrane developed behind a graft from which one half of the endothelium had been removed, and it was in this area that the membrane developed. In 1963, Bushmitch and