Posterior polymorphous corneal dystrophy-3 (PPCD3) is a rare disorder involving metaplasia and overgrowth of corneal endothelial cells (Krafchak et al., 2005). In patients with PPCD, these cells manifest in an epithelial morphology and gene expression pattern, produce an aberrant basement membrane, and sometimes spread over the iris and nearby structures in a way that increases the risk for glaucoma. Symptoms range from very aggressive to asymptomatic and nonprogressive, even within the same family. The age of diagnosis is most often in the second or third decade of life. PPCD3 is often associated with corneal steepening, and some patients may be diagnosed with keratoconus before PPCD (Fernandez-Gutierrez et al., 2023). Retrocorneal membranes have been reported, sometimes extending onto the lens (Moroi et al., 2003). For a discussion of genetic heterogeneity of posterior polymorphous corneal dystrophy, see PPCD1 (122000).

Fuchs endothelial corneal dystrophy (FECD) is a progressive, bilateral condition characterized by dysfunction of the corneal epithelium, leading to reduced vision. The prevalence of FECD has been estimated at about 5% among persons over the age of 40 years in the United States. The vision loss in patients with FECD results from a loss of corneal transparency associated with irregularity of inner corneal layers in early disease and edema of the cornea in advanced disease. Ultrastructural features of FECD include loss and attenuation of endothelial cells, with thickening and excrescences of the underlying basement membrane. These excrescences, called guttae, are the clinical hallmark of FECD and become more numerous with progression of the disease. As the endothelial layer develops confluent guttae in the central cornea, the cells are no longer able to keep the cornea dehydrated and clear (summary by Baratz et al., 2010). Genetic Heterogeneity of Fuchs Endothelial Corneal Dystrophy More common, late-onset forms of FECD have been shown to be caused by mutation in the SLC4A11 gene (610206) on chromosome 20p13 (FECD4; 613268), in the ZEB1 gene (189909) on chromosome 10p11.2 (FECD6; 613270), and in the AGBL1 gene (615496) on chromosome 15q25 (FECD8; 615523). Other loci for late-onset FECD have been identified on chromosomes 13pter-q12.13 (FECD2; 610158), 18q21.2-q21.32 (FECD3; 613267), 5q33.1-q35.2 (FECD5; 613269), and 9p (FECD7; 613271).

Late-onset Fuchs endothelial corneal dystrophy (FECD) is a degenerative disorder affecting roughly 4% of the population older than 40 years. It is distinguished from other corneal disorders by the progressive formation of guttae, which are microscopic refractile excrescences of the Descemet membrane, a collagen-rich basal lamina secreted by the corneal endothelium. From onset, it usually takes 2 decades for FECD to impair endothelial cell function seriously, leading to stromal edema and impaired vision (Sundin et al., 2006). For a discussion of genetic heterogeneity of Fuchs endothelial corneal dystrophy, see FECD1 (136800).

The appearance of yellow/white crystalline-like (hence the name) spots in the retina and thickening of the peripheral part of the vitreous.

Fuchs endothelial corneal dystrophy (FECD) is the most common genetic disorder of the corneal endothelium. Late-onset FECD is marked by thickening of Descemets membrane and excrescences, called guttae, that typically appear in the fourth or fifth decade. Disease progression results in decreased visual acuity as a result of increasing corneal edema, and end-stage disease is marked by painful epithelial bullae (summary by Riazuddin et al., 2013). Patients with keratoconus have been observed (Lechner et al., 2013). For a discussion of genetic heterogeneity of Fuchs endothelial corneal dystrophy, see FECD1 (136800).

Fuchs endothelial corneal dystrophy (FECD) is the most common genetic disorder of the corneal endothelium. Late-onset FECD is marked by thickening of Descemets membrane and excrescences, called guttae, that typically appear in the fourth or fifth decade. Disease progression results in decreased visual acuity as a result of increasing corneal edema, and end-stage disease is marked by painful epithelial bullae (summary by Riazuddin et al., 2013). For a discussion of genetic heterogeneity of Fuchs endothelial corneal dystrophy, see FECD1 (136800).

Late-onset Fuchs endothelial corneal dystrophy (FECD) is a degenerative disorder affecting roughly 4% of the population older than 40 years. It is distinguished from other corneal disorders by the progressive formation of guttae, which are microscopic refractile excrescences of the Descemet membrane, a collagen-rich basal lamina secreted by the corneal endothelium. From onset, it usually takes 2 decades for FECD to impair endothelial cell function seriously, leading to stromal edema and impaired vision (Sundin et al., 2006). For a discussion of genetic heterogeneity of Fuchs endothelial corneal dystrophy, see FECD1 (136800).

Fuchs endothelial corneal dystrophy (FECD) is the most common genetic disorder of the corneal endothelium. Late-onset FECD is marked by thickening of Descemets membrane and excrescences, called guttae, that typically appear in the fourth or fifth decade. Disease progression results in decreased visual acuity as a result of increasing corneal edema, and end-stage disease is marked by painful epithelial bullae (summary by Riazuddin et al., 2013). For a discussion of genetic heterogeneity of FECD, see FECD1 (136800).