A fluorophotometric study of the effect of argon laser trabeculoplasty on aqueous humor dynamics

Fluorophotometry and tonography were used before and after argon laser trabeculoplasty to measure aqueous humor dynamics in 15 eyes of 14 patients. A new fluorophotometric method used to measure true outflow facility showed that it increased from a mean pretreatment value of 0.016 microliter/min/mm Hg to a mean posttreatment value of 0.075 microliter/min/mm Hg. Similarly, total outflow facility, measured tonographically, increased from 0.112 microliter/min/mm Hg to 0.151 microliter/min/mm Hg. Uveoscleral flow decreased after laser therapy; however, this was secondary to the decrease in intraocular pressure. No effect was found on the rate of aqueous humor production. We concluded that the primary effect of argon laser trabeculoplasty was to increase true outflow facility, thereby decreasing intraocular pressure.