Posterior Polymorphous Corneal Dystrophy: Clinical-Pathologic Correlation.

A 9-year-old girl presented with bilateral steep corneal curvatures (A) and crater-like vacuoles in posterior cornea (B, arrow), compatible with posterior polymorphous corneal dystrophy. Penetrating keratoplasty, performed for progressive corneal stromal opacification and calcific band keratopathy (B, asterisk) demonstrated epithelial-like multilayered cells on the posterior corneal surface (C, arrowheads) and, in posterior stroma, forming vesicles (thick arrow), associated with multilamination and discontinuity in Descemet’s membrane (thin arrows) (C; hematoxylin-eosin; 1000×). These cells were positive for high molecular weight cytokeratin (D; 1000×), compatible with epithelial-like transdifferentiation of corneal endothelium. (Magnified version of Figure A-D is available online at www.aaojournal.org).