FIGURE 21.

Fuchs endothelial corneal dystrophy (FECD). A, Corneal guttae in retroillumination (i) and slit lamp view (ii). B and C, Epithelial edema with bullae and stromal edema due to endothelial decompensation. D, Light microscopy: corneal guttae in the form of focal excrescences at the level of the endothelium; thickening of Descemet membrane (arrowhead); stromal and intraepithelial edema. PAS, bar = 200 μm. E, Light microscopy: Descemet membrane endothelial keratoplasty (DMEK) specimen shows (i) thickened Descemet membrane (black arrowhead) with guttae (asterisks), which are more prominent in the central portion of the DMEK specimen (cen) when compared with the peripheral (per) section, and an attenuated endothelial cell layer (white arrowhead), PAS stain. (ii), In a corneal specimen from a different eye, the original Descemet membrane (black arrowhead) is further thickened by layers of reactively secreted looser (lr) and denser (dr) basement membrane material that buries, and in this routine HE section mostly hides earlier guttae (asterisks), the latter of which are revealed in a PAS-stained section (iii). Note sparse and flattened endothelial cells (white arrowhead); bars = 50 μm. F, In vivo confocal microscopy shows polymegethism and pleomorphism of endothelial cells associated with round hyporeflective structures sometimes containing reflective material and corresponding to guttae (400 × 400 μm). Figures 21B and C from Figures 21D and B in Weiss, JS, Møller HU, Lisch W, et al. The IC3D Classification of the Corneal Dystrophies. Cornea. 2008;27(suppl 2):S1–S42. Figures 21D and F from Figures 21D and E in Weiss, JS, Møller HU, Aldave AJ, et al. The IC3D Classification of the Corneal Dystrophies—Edition 2. Cornea. 2015;43:117–159.