Carbonic anhydrase inhibitors for the treatment of glaucoma

The bulk of aqueous humor entering the eye is produced through an active secretory process by the nonpigmented epithelial cells of the ciliary process. Carbonic anhydrase is present in these cells, and following inhibition of the enzyme, bicarbonate formation is decreased, which, in turn, diminishes sodium and fluid secretion into the eye. The biological profile of the thienothiopyrans was assessed through in vitro, ex vivo, and in vivo studies. In vitro determination of I 50 and K i values utilized HCA-II, the isozyme found in the human ciliary process