Carbonic Anhydrase and the Maintenance of Intraocular Jension

Abstract

It had previously been reported¹ that the intravenous administration of acetazoleamide (Diamox; 2-acetylamino-1,3,4-thiadiazole-5sulfonamide) inhibited * the carbonic anhydrase activity of the ciliary body-iris tissue within 30 minutes. This observation, together with a knowledge of the fundamental role of the enzyme in other tissues and cells, suggested the possibility that carbonic anhydrase may be the controlling mediator in the secretion of bicarbonate ions into the aqueous humor. In such a system the inhibition of the carbonic anhydrase activity in the anterior uvea should be reflected in a lowering of the bicarbonate ion concentration in the aqueous humor. Furthermore, according to Kinsey's postulate,² namely, that the bicarbonate ion plays a pivotal role in the formation of aqueous humor, there should also occur a drop in the intraocular pressure of the rabbit eye. In order to test the possibility that the carbonic anhydrase activity of the ciliary body controlled the secretion of