Long-Term Clinical and Safety Outcomes of Canaloplasty Performed across All Grades of Glaucoma Severity

Abstract

Purpose. To investigate the clinical effectiveness of canaloplasty performed with an ab interno technique using the iTrack microcatheter (Nova Eye Medical) in patients with mild-moderate glaucoma as compared to severe glaucoma. Methods. This is a retrospective single-center case series. Patients were preoperatively categorized as mild/moderate vs. severe glaucoma assessed using the mean deviation (MD) score and controlled group (baseline intraocular pressure (IOP) ≤18 mmHg) vs. uncontrolled group (>18 mmHg). All patients with glaucoma were eligible for recruitment except those who had undergone previous glaucoma surgery (with the exception of selective laser trabeculoplasty or SLT). Patients underwent canaloplasty via an ab interno surgical technique with or without phacoemulsification and were monitored for IOP, glaucoma medication usage, and surgical complications. Results. In total, 72 eyes were followed for 3.4 ± 0.5 years. Mean pre-op IOP (mmHg) was 19.3 ± 7.7 in the standalone group (n = 9) and 18.5 ± 5.6 in the combined group (n = 63) ( $p=0.38$ ). At the last follow-up, mean IOP reduced by 36% to 12.4 ± 4.4 ( $p=0.02$ ) in the standalone group and by 26% to 13.7 ± 4.8 in the combined group ( $p<0.001$ ). Mean pre-op IOP (mmHg) was 18.6 ± 5.2 in the severe group (n = 24) and 18.6 ± 6.2 in the mild-moderate group (n = 48) ( $p=0.48$ ). Mean IOP was 14.1 ± 6.3 (−24%; $p<0.001$ ) and 13.3 ± 3.7 (−29%; $p<0.001$ ), respectively, at the last follow-up. Mean glaucoma medication usage decreased from 2.5 ± 0.9 to 2.1 ± 0.9 (−15%; $p=0.083$ ) in the severe group and 2.3 ± 1.0 to 1.4 ± 1.3 (−40%; $p<0.001$ ) in the mild/moderate group. There was one localized Descemet’s membrane detachment in the moderate group. Conclusion. iTrack canaloplasty achieved a statistically significant IOP reduction in mild-moderate and severe eyes and was found to be an effective option for reducing IOP and medications in patients with mild-moderate primary open-angle glaucoma (POAG). In severe eyes, it has reduced IOP while the medications remained stable.