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.
Definition of COLUMNAR. 1. : of, relating to, resembling, or characterized by columns. 2. : of, relating to, being, or composed of tall narrow somewhat cylindrical or prismatic epithelial cells.See columnar defined for kids.ADVERTISEMENT. of, relating to, resembling, or characterized by columns. 2. : of, relating to, being, or composed of tall narrow somewhat cylindrical or prismatic epithelial cells. See columnar defined for kids. ADVERTISEMENT.