Ab interno canaloplasty for the treatment of glaucoma: a case series study

To describe and evaluate the efficacy of ab interno canaloplasty (ABiC) in patients with primary open-angle glaucoma (POAG).

This single-center consecutive case series study included patients with cataract and open-angle glaucoma (combined procedure) and pseudophakic patients (mean age, 76 years; range, 66-83 years) with POAG who underwent ABiC using the iTrack™ 250-μm microcatheter (Ellex Medical Lasers Pty Ltd, Adelaide, Australia) to circumferentially viscodilate and intubate Schlemm's canal without placement of a tensioning suture. The primary endpoints were mean intraocular pressure (IOP) and mean number of glaucoma medications at 1, 3, 6, 9, and 12 months postoperatively.

In total, 20 patients (20 eyes) were enrolled in the study. Mean IOP reduced from 18.5 ± 3.44 mm Hg preoperatively to 14.88 ± 2.82 mm Hg (n = 17), 13.80 ± 2.05 (n = 12), 14.57 ± 2.59 mm Hg (n = 9) and 15.47 ± 2.42 (n = 6) at 1, 3, 6 and 9 months postoperatively. The 12‑month data for two patients showed that IOP had reduced from 17 mm Hg preoperatively to 16 mm Hg in one patient and from 20 mm Hg to 13 mm Hg in the other patient. The mean number of medications was reduced from 2.4 preoperatively to 0.25 at the last follow-up visit. There was one reported complication of limited descemetolysis near the limbus by the viscoelastic during the dilatation of Schlemm's canal. No adverse events as a result of the device were reported.

ABiC was straightforward to perform in this group of patients with minimal complications. Although initial findings from this study indicate that ABiC is comparable to conventional canaloplasty in lowering IOP and medication dependency, long-term follow-up in a large patient cohort is required to confirm the efficacy of this minimally invasive glaucoma procedure.