In Fuchs' endothelial dystrophy the endothelial cells that secrete Descemet's apparently are in poor control (metabolically speaking) and cause wart like excrescences to form in groups primarily in the center of the cornea. The excrescences are known as guttae. Figure 22 shows the normal endothelial cells (a) as well as the guttae (b). When looking by specular techniques we see guttae as dark spots which blend with the borders of endothelial cells.  The cells may thin while overlying the excrescences and eventually be absent in the area of the guttae. Figure 23 shows the origin of the guttae (a) as well as the formation of the specular image. Appearance of normal endothelial cells (a) and guttae (b) (Figure 22) Illustration demonstrating appearance, mechanism of formation, and the specular reflection seen with guttatae. (Figure 23) Table of Contents Next Section