Multiple trabecular microstents combined with phaco reduce IOP

SAN DIEGO — Implantation of two or three trabecular microstents in combination with phacoemulsification safely diminished IOP, according to a study presented here.

"A single trabecular bypass can increase outflow facility," Ike K. Ahmed, MD, FRCSC, said at the American Glaucoma Society meeting. "Multiple bypasses may further reduce the pressure as well."

He said that 50% to 90% of resistance to aqueous outflow occurs in the trabecular meshwork, and multiple stents placed throughout Schlemm's canal may increase outflow into distal pathways.

The prospective study included 25 patients with open-angle glaucoma who underwent combined phacoemulsification and implantation of the iStent (Glaukos); 14 patients received two stents and 11 patients received three stents.

Mean IOP was reduced from 20.5 mm Hg preop to 13.2 mm Hg at 6 months follow-up (P < .001). Patients who received three stents used fewer medications than those who received two stents. No postoperative complications were reported.

"I think our findings are consistent with theoretical, histological and clinical findings that have been shown in the past," Dr. Ahmed said. "This may provide an ability to heighten the number of implants based on the disease severity and target pressure."

The iStent is undergoing U.S. Food and Drug Administration clinical trials.