The role of the trabecular meshwork cells in glaucoma has not been clarified. A major problem has been the lack of a system in vitro in which the characteristics of trabecular meshwork cells can be studied. Recently, we have propagated trabecular cells from a number of human sources in continuous culture. These cells have unique properties that distinguish them from neighboring cells of the eye. In addition, trabecular meshwork cells in vitro: 1) produce hyaluronic acid and other connective tissue elements similar to intact tissue; 2) have structural and cytological features similar to intact tissue; 3) demonstrate active phagocytic properties; and 4) have glucocorticoid and catecholamine receptors and respond to physiological levels of these two hormones. In the current proposal we hope to examine further the biological properties of cultured trabecular cells. Initial efforts will be directed at establishing conditions for optimal cell growth. Particular emphasis will be given to a detailed investigation of the differentiated functions, such as connective tissue metabolism and phagocytosis, which may have a potential importance to primary and secondary glaucoma. It is hoped that these studies will provide a better basis for understanding the function of trabecular cells and that the information gained may provide new therapeutic approaches to glaucoma.