Canaloplasty shows favorable outcomes in patients with OAG

September 1, 2007

Canaloplasty is being evaluated in an ongoing prospective study that enrolled 94 patients who were candidates for glaucoma surgery. An interim analysis was performed from follow-up through 12 months and showed that the procedure resulted in safe and effective reductions in IOP.

Key Points

In a recently published paper (J Cataract Refract Surg 2007; 33:1217-1226), Richard A. Lewis, MD and colleagues reported 12-month follow-up data for the ongoing international, multicenter clinical trial evaluating the safety and efficacy of canaloplasty in 94 patients at 14 clinical sites. The procedure involves nonpenetrating dissection to expose Schlemm's canal, circumferential viscodilation of the canal using a flexible microcatheter (iTrack 250A, iScience Interventional), and placement of a trabecular tensioning suture.

At baseline, mean IOP was 24.7 mm Hg, and patients were using an average of 1.9 medications. Complete circumferential catheterization of the canal and successful suture placement was accomplished in 74 eyes. Considering the latter subgroup, mean IOP was 15.3 mm Hg at 12 months after surgery, and mean glaucoma medication usage was reduced to 0.6 agents per patient. Safety assessment revealed few complications.

"Canaloplasty differs from other nonpenetrating procedures in that it uses the full 360 of the outflow system and applies inward-directed tension on the trabecular meshwork through suture placement. Follow-up in the present study is planned through 5 years, but we now have data available through 18 months, and the results indicate this new modification of nonpenetrating surgery is keeping IOP well-controlled," Dr. Lewis said.

All patients enrolled in the study were candidates for glaucoma surgery and had an IOP 16 mm Hg recorded within 60 days prior to surgery and no previous IOP exceeding 21 mm Hg. Eighty-four (89%) of the 94 patients had a diagnosis of primary OAG.

Patients who required phacoemulsification with posterior chamber IOL implantation were eligible for study enrollment. A total of 27 patients (29%) underwent combination cataract extraction, PC IOL implantation, and canaloplasty. Compared with eyes that underwent canaloplasty alone, the mean percent reduction in IOP from baseline was significantly greater in the combined group at 12 months (46% versus 33%).