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.
Hyperplasia is increased cell production in a normal tissue or organ. Hyperplasia may be a sign of abnormal or precancerous changes. This is called pathologic hyperplasia. It can also be due to the growth of completely normal cells.