Effectiveness and Safety of Combined Ab-Interno Canaloplasty and Microstent Implantation in Severe Glaucoma – A Retrospective Study

Justin Spaulding Cataract & Laser Institute of Southern Oregon, Medford, OR, USACorrespondence: Justin Spaulding, Cataract & Laser Institute of Southern Oregon, 1408 E Barnett Road, Medford, OR, 97504, USA, Tel +1 541 779 2020, Email [email protected]: To evaluate the efficacy and safety of ab-interno canaloplasty combined with microstent implantation in patients with severe glaucoma.Patients and Methods: This retrospective study included patients with severe glaucoma (mean age 74.6± 8.7 years), predominantly primary open-angle (90%). All eyes underwent combined ab-interno canaloplasty using the iTrack (Nova Eye Medical) with concurrent Hydrus Microstent (Alcon) implantation during cataract surgery. The primary outcome measures were intraocular pressure (IOP), number of glaucoma medications, visual field mean deviation (VFMD), postoperative complications.Results: Sixty-nine eyes of 56 patients were followed for mean 27.9± 13.8 months. Mean IOP decreased from 17.8± 6.3 at baseline to 15.5± 4.7 mmHg at last follow-up (p=0.012), and mean number of medications decreased by 47%, from 2.10± 1.1 to 1.12± 1.2 (p< 0.001). Medication-free eyes increased from 7% at baseline to 43% at last follow-up. Among eyes that were on 3 and 4 medications preoperatively (n=17; n=7), the number of medications significantly decreased by 53% (p< 0.001) and 57% (p=0.002) at last follow-up, while IOP remained stable. Eyes with baseline IOP > 18 mmHg (n=21) experienced a significant mean IOP reduction of 9.8 mmHg (from 24.8± 6.7 to 15.0± 4.6 mmHg; − 40%, p< 0.001). No intraoperative or postoperative complications were reported; 6 eyes (9%) required additional glaucoma procedures during follow-up.Conclusion: Combining ab-interno canaloplasty with Hydrus Microstent implantation during cataract surgery resulted in modest but sustained reductions in intraocular pressure and glaucoma medication burden, with a favorable safety profile. However, postoperative IOP frequently remained above levels required for very low target pressures. These findings suggest that this mixed MIGS approach may be considered in carefully selected patients but should not be viewed as a substitute for traditional filtering surgery in advanced disease.Keywords: primary open-angle glaucoma, minimally invasive glaucoma surgery, MIGS canaloplasty, Hydrus Microstent, combined MIGS, IOP reduction