A pharmacologist looks at medical treatment in glaucoma--in retrospect and in prospect.

The histochemical distribution of carbonic anhydrase activity in the ciliary processes is shown. There is a multiplicity of possible points of attack of carbonic anhydrase inhibitors, We do not know which sites are critically inhibited at clinical dosage. One primary mechanism of the therapeutic action of miotics is ciliary muscle contraction, but on prolonged treatment, subsensitivity of the muscle may shift emphasis to miotic inhibition of aqueous secretion by unknown mechanisms. The trabecular meshwork is a slow tissue living off the aqueous. Aqueous composition in chronic simple glaucoma should therefore be studied with a view to possible treatment of the sick meshwork.