Members of the DEWS Definition and Classification. Subcommittee developed a contemporary definition of dry eye disease and a three-. part classification system based on etiology, causative mechanisms and disease. severity.
Metaplasia. Definition: Metaplasia is the reversible replacement of one differentiated cell type with another differentiated cell type. Metaplasia causes precursor cells to change their cell fate, and do not change existing differentiated cells.he most common epithelial metaplasia is columnar to squamous (squamous metaplasia), as occurs in the respiratory tract in response to chronic irritation.
Metaplasia. The change in epithelium from one type to another. Ex: Smokers irritate the linings of their airways enough to induce the change from pseudostratified columnar epithelium to stratified squamous epithelium, which is more resistant to stress. This process is reversible.