Clinicopathologic findings in iridocorneal endothelial syndrome and posterior polymorphous membranous dystrophy after descemet stripping automated endothelial keratoplasty

Purpose: To report the histopathologic findings of the iridocorneal endothelial (ICE) syndrome and posterior polymorphous membranous dystrophy (PPMD) in 3 patients who underwent Descemet stripping automated endothelial keratoplasty (DSAEK), and to correlate these findings with the clinical diagnosis. Methods: Three patients with clinical findings compatible with either ICE syndrome (1 patient) or PPMD (2 patients) underwent DSAEK. The DSAEK specimens were processed for light microscopy, immunhistochemical staining for cytokeratins AE1/3 and MAK6, and electron microscopy. Results: Examination of the DSAEK specimens showed multilayered endothelial cells and thickened Descemet membrane in all cases. Immunohistochemical staining for cytokeratins was positive in the endothelium in all cases. Ultrastructural examination showed a thickened Descemet membrane and wide-spaced collagen in Descemet membrane in 1 case of PPMD but not in 2 cases of ICE syndrome, including 1 case that carried the clinical diagnosis of PPMD. In 2 cases, the histopathologic evaluation of the DSAEK specimen confirmed the clinical diagnosis; however, in 1 case the pathological diagnosis was ICE syndrome, while the clinical diagnosis was PPMD. Conclusions: ICE syndrome and PPMD can be diagnosed and differentiated from one another by histopathologic evaluation of corneal specimens obtained at the time of DSAEK. We recommend submitting the corneal tissue obtained during DSAEK for pathological examination when the etiology of corneal edema is unclear.