Venous pressure opposing aqueous outflow in patients with and without chronic open-angle glaucoma. Calculation from data obtained by indentation tonography and suction cup analysis using an electrical model of the eye.

Three groups of patients (those with chronic open-angle glaucoma, glaucoma suspects, and normals) were subjected to both tonography and suction cup analysis. The data, analyzed by an electrical model of the eye, showed that (1) venous pressure opposing aqueous outflow is higher in patients with chronic open-angle glaucoma and in glaucoma suspects than in normal patients; and (2) lack of pressure rise during the time that a perilimbal suction cup is applied to the eye may not be the restdt of faulty technique, as has been previously assumed, but may indicate inflow less than the stress relaxation of the ocular coats. The residts confirm that (1) patients with chronic open-angle glaucoma have a decreased facility of outflow, independent of other parameters; and (2) patients on both acetazolamide and epinephrine therapy have a decreased aqueous production.