Effect of trabecular photocoagulation on the aqueous humor dynamics of the human eye

A group of 17 patients (ten men and seven women, ranging in age from 56 to 79 years) who had either chronic simple glaucoma or open-angle glaucoma and the exfoliation syndrome (pseudexfoliation) underwent argon laser trabeculoplasty in one eye each. Shortly before and three months after this procedure, both eyes underwent a number of tests to determine the physiologic status of the aqueous circulation, the blood-ocular barrier, and the cornea. A therapeutically significant decrease in intraocular pressure was observed in nine of the 17 treated eyes (mean pretreatment value for the 17 eyes, 21 +/- 5 mm Hg; mean posttreatment value, 14 +/- 4 mm Hg). This decrease was associated with an improvement in the tonographic facility of outflow (mean pretreatment value, 0.11 +/- 0.05 microliter/min/mm Hg; mean posttreatment value, 0.18 +/- 0.08 microliter/min/mm Hg). Apparent resistance to aqueous outflow decreased from a mean pretreatment value of 14.2 +/- 4.5 min . mm Hg/microliter to mean posttreatment value of 9.2 +/- 3.0 min . mm Hg/microliter). The other variables showed only small, statistically insignificant changes.