Aqueous Flow Measurements in Man by the Perilimbal Suction Cup Technique. Ii. Comparisons in Chronic Simple Glaucoma before and after Pilocarpine.

WITH the observation by Laqueur (1876) that tension of glaucomatous eyes could be reduced with physostigmine, and the corroboration of Weber (1877) that the same effect attended the use of pilocarpine, both substances have found a permanent place in therapy. Their precise action, however, remains obscure (Sugar, 1957; Becker and Shaffer, 1961). Unlike carbonic anhydrase inhibitors, such as acetazolamide, which lower the intra-ocular pressure in glaucoma by reducing the rate of aqueous formation without alteration of the outflow facility, pilocarpine relieves the obstructed outflow of aqueous in glaucoma. This effect might be explained either by a direct action upon the aqueous outflow episcleral veins or by a direct reduction in the rate of aqueous formation. The suction cup technique, introduced by Ericson (1958) provides measurements of: