Four-Year Efficacy and Safety of iTrack Ab-interno Canaloplasty as a Standalone Procedure and Combined with Cataract Surgery in Open-Angle Glaucoma

Abstract

Purpose To evaluate the long-term effectiveness of ab-interno canaloplasty (ABiC), performed with the iTrack microcatheter (Nova Eye Medical, Fremont, CA, USA), in reducing intraocular pressure (IOP) as well as the number of required glaucoma medications in patients with open-angle glaucoma (OAG).

Methods In this retrospective single-center consecutive case series, 27 eyes of 21 patients (mean age 77.3 ± 5.8 years) were treated with ABiC performed as a standalone procedure or combined with cataract surgery. Patients with uncontrolled IOP OAG or controlled IOP (≤ 18 mmHg) OAG with intolerance to medications or lack of compliance were included. Patients were followed for up to 4 years following the procedure. The iTrack microcatheter was used to perform a 360-degree circumferential intubation and viscodilation of Schlemmʼs canal. Primary efficacy endpoints included IOP and the number of glaucoma medications at 12, 24, 36, and 48 months after surgery.

Results In all eyes, mean IOP and number of glaucoma medications were significantly reduced from 19.8 ± 5.2 mmHg and 1.9 ± 1.00 at baseline to 14.6 ± 3 mmHg and 0.9 ± 0.8, respectively, at the 48-month follow-up (p < 0.001). IOP was stable from 12 months to 48 months (p > 0.005). After 48 months, 39% of the eyes required zero medications compared to 3.7% at baseline, and 72.2% of eyes required only one medication or less. Of all eyes, 77.8% recorded an IOP ≤ 17 mmHg. No serious complications were recorded.

Conclusion iTrack ABiC performed as a standalone procedure or in combination with cataract surgery significantly reduced IOP and number of medications in patients with OAG up to 4 years after the procedure.

Zusammenfassung

Zweck Ziel war die Ermittlung der Langzeitwirksamkeit der Ab-interno-Kanaloplastik (ABiC) mittels iTrack-Katheter (Nova Eye Medical, Fremont, CA, USA) in Patienten mit primärem Offenwinkelglaukom (POAG) durch die Senkung des Augeninnendrucks (IOP) und der Zahl der benötigten Glaukommedikamente.

Methoden In dieser retrospektiven, monozentrischen konsekutiven Fallserie wurden 27 Augen von 21 Patienten (Durchschnittsalter: 77,3 ± 5,8 Jahre) mit ABiC als Stand-alone-Eingriff oder in Kombination mit einer Kataraktoperation behandelt. Einbezogen wurden Patienten mit kontrolliertem IOP (≤ 18 mmHg) und unkontrolliertem IOP (> 18 mmHg). Aufgrund von Medikamentenunverträglichkeiten oder mangelnder Compliance wurde bei Patienten mit kontrolliertem IOP die ABiC zur Minimierung der erforderlichen Medikamente durchgeführt und sie wurden anschließend bis zu 4 Jahre lang beobachtet. Der iTrack-Mikrokatheter wurde zur 360°-zirkumferenziellen Intubation und Viskodilatation des Schlemm-Kanals verwendet. Primäre Wirksamkeitsendpunkte der Studie waren der IOP und die Glaukommedikamentenzahl bis 12, 24, 36 und 48 Monate nach dem Eingriff.

Ergebnisse Bei allen Augen wurden der mittlere IOP und die Glaukommedikamentenzahl signifikant von 19,8 ± 5,2 mmHg und 1,9 ± 1 zu Beginn der Studie jeweils auf 14,6 ± 3 mmHg und 0,9 ± 0,8 bei der 48-monatigen Nachuntersuchung reduziert (p < 0,001). Der IOP und die Medikamentenzahl waren von 12 bis 48 Monaten stabil (p > 0,005). Nach 48 Monaten benötigten 39% der Augen keine Medikamente, verglichen mit 3,7% zu Studienbeginn, und 72,2% der Augen benötigten nur ein Medikament oder weniger. 77,8% der Augen wiesen einen IOP ≤ 17 mmHg auf. Es wurden keine ernsthaften Komplikationen verzeichnet.

Schlussfolgerung Als Stand-alone-Eingriff oder in Kombination mit einer Kataraktoperation reduzierte die iTrack-ab-interno-Kanaloplastik signifikant den IOP und die Medikamentenzahl bei Patienten mit POAG bis zu 4 Jahre nach dem Eingriff.

Key words

intraocular pressure - ab-interno canaloplasty - MIGS - canaloplasty - minimally invasive glaucoma surgery - open-angle glaucoma

Schlüsselwörter

Augeninnendruck - Kanaloplastik ab interno - MIGS - Kanaloplastik - Offenwinkelglaukom

Publication History

Received: 29 April 2021

Accepted: 21 December 2021

Article published online:
14 April 2022

• References

• 1 Tham YC, Li X, Wong TY. et al. Global prevalence of glaucoma and projections of glaucoma burden through 2040: a systematic review and meta-analysis. Ophthalmology 2014; 121: 2081-2090
• 2 Leske MC, Heijl A, Hyman L. et al. Early Manifest Glaucoma Trial: design and baseline data. Ophthalmology 1999; 106: 2144-2153
• 3 Lavia C, Dallorto L, Maule M. et al. Minimally-invasive glaucoma surgeries (MIGS) for open angle glaucoma: A systematic review and meta-analysis. PLoS ONE 2017; 12: e0183142
• 4 Olthoff CMG, Schouten JS, van de Borne BW. et al. Noncompliance with ocular hypotensive treatment in patients with glaucoma or ocular hypertension: an evidence-based review. Ophthalmology 2005; 112: 953-961.e7
• 5 Rossi GCM, Pasinetti GM, Scudeller L. et al. Do adherence rates and glaucomatous visual field progression correlate?. Eur J Ophthalmol 2011; 21: 410-414
• 6 Newman-Casey PA, Robin AL, Blachley T. et al. The Most Common Barriers to Glaucoma Medication Adherence: A Cross-Sectional Survey. Ophthalmology 2015; 122: 1308-1316
• 7 Beckers HJ, Schouten JS, Webers CA. et al. Side effects of commonly used glaucoma medications: comparison of tolerability, chance of discontinuation, and patient satisfaction. Graefes Arch Clin Exp Ophthalmol 2008; 246: 1485-1490
• 8 Ammar DA, Kahook MY. Effects of benzalkonium chloride- or polyquad-preserved fixed combination glaucoma medications on human trabecular meshwork cells. Mol Vis 2011; 17: 1806-1813
• 9 Last JA, Pan T, Ding Y. et al. Elastic modulus determination of normal and glaucomatous human trabecular meshwork. Invest Ophthalmol Vis Sci 2011; 52: 2147-2152
• 10 Razeghinejad MR, Spaeth GL. A history of the surgical management of glaucoma. Optom Vis Sci 2011; 88: E39-E47
• 11 Borisuth N, Phillips B, Krupin T. The risk profile of glaucoma filtration surgery. Curr Opin Ophthalmol 1999; 10: 112-116
• 12 Francis BA, Singh K, Lin SC. et al. Novel glaucoma procedures: a report by the American Academy of Ophthalmology. Ophthalmology 2011; 118: 1466-1480
• 13 Saheb H, Ahmed IIK. Micro-invasive glaucoma surgery: current perspectives and future directions. Curr Opin Ophthalmol 2012; 23: 96-104
• 14 Khaimi MA. Canaloplasty: A Minimally Invasive and Maximally Effective Glaucoma Treatment. J Ophthalmol 2015; 2015: 485065
• 15 Gallardo MJ, Supnet RA, Ahmed IIK. Circumferential viscodilation of Schlemmʼs canal for open-angle glaucoma: ab-interno vs. ab-externo canaloplasty with tensioning suture. Clin Ophthalmol 2018; 12: 2493-2498
• 16 Gallardo MJ, Supnet RA, Ahmed IIK. Viscodilation of Schlemmʼs canal for the reduction of IOP via an ab-interno approach. Clin Ophthalmol 2018; 12: 2149-2155
• 17 Kazerounian S, Zimbelmann M, Lörtscher M. et al. Canaloplasty ab interno (AbiC) – 2-Year-Results of a Novel Minimally Invasive Glaucoma Surgery (MIGS) Technique. Klin Monbl Augenheilkd 2021; 238: 1113-1119
• 18 Hodapp E, Parrish RKI, Anderson DR. Clinical decisions in glaucoma. St. Louis: The CVMosby Co.; 1993
• 19 [Anonymous] European glaucoma society terminology and guidelines for glaucoma, 4th edition – Chapter 2: Classification and terminology Supported by the EGS Foundation: Part 1: Foreword; Introduction; Glossary; Chapter 2 classification and terminology. Br J Ophthalmol 2017; 101: 73-127
• 20 Lewis RA, von Wolff K, Tetz M. et al. Canaloplasty: Three-year results of circumferential viscodilation and tensioning of Schlemm canal using a microcatheter to treat open-angle glaucoma. J Cataract Refract Surg 2011; 37: 682-690
• 21 Gallardo MJ. 24-Month Efficacy of Viscodilation of Schlemmʼs Canal and the Distal Outflow System with Itrack Ab-Interno Canaloplasty for the Treatment of Primary Open-Angle Glaucoma. Clin Ophthalmol 2021; 15: 1591-1599
• 22 Godfrey DG, Fellman RL, Neelakantan A. Canal surgery in adult glaucomas. Curr Opin Ophthalmol 2009; 20: 116-121
• 23 Craven ER, Katz LJ, Wells JM. et al. Cataract surgery with trabecular micro-bypass stent implantation in patients with mild-to-moderate open-angle glaucoma and cataract: two-year follow-up. J Cataract Refract Surg 2012; 38: 1339-1345
• 24 Pfeiffer N, Garcia-Feijoo J, Martinez-de-la-Casa JM. et al. A Randomized Trial of a Schlemmʼs Canal Microstent with Phacoemulsification for Reducing Intraocular Pressure in Open-Angle Glaucoma. Ophthalmology 2015; 122: 1283-1293
• 25 Pahlitzsch M, Gonnermann J, Maier AKB. et al. [Trabeculectomy ab Interno in primary open angle glaucoma and exfoliative glaucoma]. Klin Monbl Augenheilkd 2015; 232: 1198-1207
• 26 Fea AM. Phacoemulsification versus phacoemulsification with micro-bypass stent implantation in primary open-angle glaucoma. Randomized double-masked clinical trial. J Cataract Refract Surg 2010; 36: 407-412
• 27 Hengerer FH, Auffarth GU, Riffel C. et al. Prospective, Non-randomized, 36-Month Study of Second-Generation Trabecular Micro-Bypass Stents with Phacoemulsification in Eyes with Various Types of Glaucoma. Ophthalmol Ther 2018; 7: 405-415
• 28 Samuelson TW, Sarkisian SRJ, Lubeck DM. et al. Prospective, Randomized, Controlled Pivotal Trial of an Ab Interno Implanted Trabecular Micro-Bypass in Primary Open-Angle Glaucoma and Cataract: Two-Year Results. Ophthalmology 2019; 126: 811-821
• 29 Majstruk L, Leray B, Bouillot A. et al. Long term effect of phacoemulsification on intraocular pressure in patients with medically controlled primary open-angle glaucoma. BMC Ophthalmol 2019; 19: 149
• 30 Mathalone N, Hyams M, Neiman S. et al. Long-term intraocular pressure control after clear corneal phacoemulsification in glaucoma patients. J Cataract Refract Surg 2005; 31: 479-483
• 31 Shingleton BJ, Pasternack JJ, Hung JW. et al. Three and five year changes in intraocular pressures after clear corneal phacoemulsification in open angle glaucoma patients, glaucoma suspects, and normal patients. J Glaucoma 2006; 15: 494-498
• 32 Kozera M, Konopińska J, Mariak Z. et al. Effectiveness of iStent trabecular micro-bypass system combined with phacoemulsification vs. phacoemulsification alone in patients with glaucoma and cataract depending on the initial intraocular pressure. Ophthalmic Res 2020; 64: 327-336
• 33 Davids AM, Pahlitzsch M, Boeker A. et al. Ab interno canaloplasty (ABiC)–12-month results of a new minimally invasive glaucoma surgery (MIGS). Graefes Arch Clin Exp Ophthalmol 2019; 257: 1947-1953
• 34 Ondrejka S, Koerber N. 360° ab-Interno Schlemmʼs canal viscodilation in primary open-angle glaucoma. Clin Ophthalmol 2019; 13: 1235-1246
• 35 Koerber N. Ab interno canaloplasty for the treatment of glaucoma: a case series study. Spektrum Augenheilkd 2018; 32: 223-227
• 36 Brüggemann A, Despouy JT, Wegent A. et al. Intraindividual comparison of Canaloplasty versus trabeculectomy with mitomycin C in a single-surgeon series. J Glaucoma 2013; 22: 577-583
• 37 [Anonymous] Multicenter Ab-interno Glaucoma Study Investigating Canaloplasty (MAGIC). ClinicalTrials.gov. Identifier: NCT04769453. 2021 Accessed March 1, 2021 at: https://clinicaltrials.gov/ct2/show/NCT04769453