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). [from
OMIM]