Thelansis

  Fuchs endothelial dystrophy (FED) is a primary, progressive corneal endothelial disorder that causes corneal edema and vision loss. The first signs of FED usually appear between the fifth and seventh decades of life. They are characterized by progressive accumulation of focal excrescences, termed “guttae,” and thickening of Descemet’s membrane, a collagen-rich layer secreted by endothelial cells. Endothelial cell density and functionality as the cornea's "pump" eventually decline, resulting in vision-threatening corneal edema. Although the presence of corneal guttae is not pathognomonic for FED, the development of stromal edema does. Symptoms include visual blurring, most notably in the morning, and stromal and epithelial edema caused by relatively low tear film osmolality. FED has been linked to mutations in collagen VIII, a vital component of the Descemet's membrane secreted by endothelial cells. FED is divided into four stages, beginning with early signs of gutta...