Multicentre study comparing ab-interno canaloplasty and trabecular micro-bypass stent in primary open-angle glaucoma

To compare canaloplasty and trabecular micro-bypass surgery outcomes in primary open-angle glaucoma (POAG).

Ambispective study using data from the International Glaucoma Surgery Registry (IGSR) to evaluate mild-to-moderate POAG patients who underwent iTrack ab-interno canaloplasty (Nova Eye Medical, USA) (prospective cohort) or iStent trabecular micro-bypass implantation (Glaukos, USA) (retrospective cohort), with or without concomitant phacoemulsification, and ≥12 months of follow-up. Primary outcomes were intraocular pressure (IOP), medication usage, and surgical success as defined by the American Academy of Ophthalmology (2024).

The study included 339 eyes (iStent: n = 115; iTrack: n = 224) of which ≥94% underwent concomitant phacoemulsification (iStent: n = 109, iTrack: n = 210). There were nonsignificant differences in baseline IOP (p = 0.417) and medications (p = 0.741) between groups. At last follow-up, mean IOP (mmHg) and medication usage decreased from 17.3 ± 4.2 and 2.0 ± 1.1 at baseline to 14.2 ± 3.5 and 1.3 ± 1.1 in the iStent group (p < 0.001; mean follow-up: 27.2 ± 14.5 months), and from 16.9 ± 5.0 and 2.0 ± 1.1 at baseline to 14.3 ± 3.4 and 1.1 ± 1.3 in the iTrack group (p < 0.001; mean follow-up: 20.3 ± 7.7 months). Both groups showed no significant differences in reduction of IOP (p = 0.422) and medications (p = 0.211). More eyes were medication-free in the iTrack group (42% vs 29%; p = 0.029). Success was achieved in 61% of eyes in both groups (p = 1.000). Postoperatively, both groups demonstrated infrequent and self-limited complications, no sight-threatening events, and low reoperation rates.

In POAG, iTrack canaloplasty and iStent implantation showed no statistically significant differences in effectiveness outcomes. Both procedures had favourable safety profiles with limited additional glaucoma surgeries. More canaloplasty eyes were medication-free compared to stent eyes.