Epithelial basement membrane dystrophy (EBMD, also called map-dot-fingerprint dystrophy). A, Clinical appearance, showing fine, lacy opacities (arrows). B, Retroillumination demonstrating wavy lines (arrow) and dotlike lesions (arrowhead). C, The changes in primary EBMD are essentially identical to those seen in cases of chronic corneal edema secondary to endothelial decompensation. Note the intraepithelial basement membrane (BM) highlighted with PAS stain and the degenerating epithelial cells trapped within cystoid spaces (C). D, When surgical treatment is required for EBMD, removal of abnormal epithelium (superficial keratectomy) may be performed, as in this case. PAS stain highlights folding and thickening (arrowheads) of the epithelial basement membrane.