Performed via an ab-interno approach, iTrack™ is an atraumatic, tissue-sparing procedure that achieves excellent clinical outcomes while also preserving the viability of future treatment options. Based on the same principles as angioplasty, iTrack™ combines 360-degree pressurized viscodilation with 360-degree catheterization of Schlemm’s canal to remove outflow resistance in the trabecular meshwork, Schlemm’s canal and the distal outflow system, including the collector channel ostia – thereby reducing intraocular pressure (IOP) and reducing patient dependence on medications.
"While various MIGS devices may work on specific sections of the outflow system, the multiple mechanisms of iTrack™ let us hedge our bets and, in my opinion, give us a better chance of getting that reduction of pressure in the right type of patient population."
The iTrack™ procedure addresses all resistance sites, including the collector channel ostia, to effectively reduce IOP and medication dependence without causing any physiological changes, and without leaving behind a stent or shunt. iTrack™ is suitable for both phakic and pseudophakic patients.
"I think that iTrack™ comprehensively treats outflow locations, which is why it is my first go-to MIGS procedure. I don't have the diagnostic capability to know where the obstruction is located or what level of resistance exists, so I like to start off with a MIGS that addresses everything."
1. Stegmann R, Pienaar A, Miller D. Viscocanalostomy for open-angle glaucoma in black African patients. J Cataract Refract Surg. 1999;25(3):316 – 322.2. Grieshaber MC, Pienaar A, Olivier J, Stegmann R. Clinical evaluation of the aqueous outflow system in primary open-angle glaucoma for canaloplasty. Invest Ophthalmol Vis Sci. 2010;51(3):1498 – 1504.3. Gillman K, Mansouri K, Ambresin A, Bravetti G, Mermoud A. A Prospective Analysis of iStent Inject Microstent Implantation: Surgical Outcomes, Endothelial Cell Density, and Device Position at 12 Months. J Glaucoma. Volume 29, Number 8, August 2020. https://pubmed.ncbi.nlm.nih.gov/32433094/4. Shiba D, Hosoda S, Yaguchi S, Ozeki N, Yuki K, Tsubota K. Safety and Efficacy of Two Trabecular Micro-Bypass Stents as the Sole Procedure in Japanese Patients with Medically Uncontrolled Primary Open-Angle Glaucoma: A Pilot Case Series. J Ophthalmol. 2017; 2017: 9605461. Published online 2017 Feb 7. https://pubmed.ncbi.nlm.nih.gov/28265466/ 5. Popovic M, Campos-Moller X, Saheb H, Ahmed IIK. Efficacy and Adverse Event Profile of the iStent and iStent Inject Trabecular Micro-bypass for Open-angle Glaucoma: A Meta-analysis. J Curr Glaucoma Pract 2018;12(2):67 – 84.
https://pubmed.ncbi.nlm.nih.gov/30473602/ 6. ElMallah MK, Seibold LK, Kahook MY et al. 12-Month Retrospective Comparison of Kahook Dual Blade Excisional Goniotomy with iStent Trabecular Bypass Device Implantation in Glaucomatous Eyes at the Time of Cataract Surgery. Adv Ther 36, 2515 – 2527 (2019). https://pubmed.ncbi.nlm.nih.gov/31317390/7. Gallardo MJ, Supnet RA, Ahmed IIK. Viscodilation of Schlemm’s canal for the reduction of IOP via an ab-interno approach. Clinical Ophthalmology. Vol 12. August 2018.
Studies undertaken in human POAG eyes by Haiyan Gong, MD, PhD (University of Boston) have demonstrated that many collector channels may be blocked with herniated trabecular meshwork, with these blockages becoming progressively worse as IOP rises1. Specifically, Gong demonstrated that 61% of collector channel ostia were blocked by herniations of the trabecular meshwork in POAG eyes. These herniations into the collector channel ostia result in increased outflow resistance.
The dimensions of the lumen of Schlemm’s canal are smaller in POAG eyes, resulting in increased outflow resistance. It has been postulated that this reduction in Schlemm’s canal dimensions may account for approximately half of the decrease in outflow facility observed in POAG eyes.1
“Not only does iTrack™ break the herniations that we see in the canal, but it also viscodilates. So, it's really pushing out the entire distal channel and also opening up the trabecular meshwork.”
The iTrack™ is the only device that can achieve pressurized viscodilation in order to stretch the trabecular meshwork and to create microperforations into the anterior chamber. It can also push out herniations of the collector channel ostia.
With the iTrack™ you can adjust the amount of OVD delivered in accordance with the patient’s pathology to deliver more, or less, OVD as required.
A malleable yet rigid internal guide wire within the iTrack™microcatheter minimizes the risk of creating an artificial pathway. It also enables you to push through herniations and to maneuver through tight areas of the canal.
The iTrack™ microcatheter features a proprietary illuminated fiberoptic tip that provides continuous location feedback. It also helps to safeguard against misdirection into the suprachoroidal space or the collector channels.
“What's so nice about iTrack™ is the fact that we can control how much viscoelastic we're pushing into Schlemm's canal, and to see distension of the canal by up to two or three times.”
REFERENCESGallardo MJ, Supnet RA, Ahmed IIK. Viscodilation of Schlemm’s canal for the reduction of IOP via an ab-interno approach. Clinical Ophthalmology. Vol 12. August 2018.
Körber N. Ab interno canaloplasty for the treatment of glaucoma: a case series study. Spektrum Augenheilkd (2018) 32:223227
Gallardo MJ, Supnet RA, Ahmed IIK. Circumferential Viscodilation of Schlemms Canal for Open-Angle Glaucoma: ab-interno vs ab-externo canaloplasty with tensioning suture. Clinical Ophthalmology 2018:12 24932498Lubeck DM, Singh IP, Noecker RJ. Evaluation of Endothelial Cell Density and Loss Following iTrack Ab-Interno Canal Based Surgery. ASCRS 2020 (Paper Presentation). https://ascrs.confex.com/ascrs
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. 37, 682 – 690 (2011).
Stegmann R, Pienaar A, Miller D. Viscocanalostomy for open-angle glaucoma in black African patients. J Cataract Refract Surg. 1999;25(3):316 – 322.
Grieshaber MC, Pienaar A, Olivier J, Stegmann R. Clinical evaluation of the aqueous outflow system in primary open-angle glaucoma for canaloplasty. Invest Ophthalmol Vis Sci. 2010;51(3):1498 – 1504.
Smit BA, Johnstone MA. Effects of viscoelastic injection into Schlemm’s canal in primate and human eyes: potential relevance to viscocanalostomy. Ophthalmology. 2002;109(4):786 – 792.
Fellman RL, Grover DS. Episcleral venous fluid wave: intraoperative evidence for patency of the conventional ouflow system. J Glaucoma. 2014;23(6):347 – 350.
Gong H, et al. Reduction of the available area for Aqueous humor outflow and increase in meshwork herniations into collector channels following acute IOP elevation in bovine eyes. Invest. Ophthalmol Vis Sci 2008; 49:5346 – 5352.
Gong H and Francis A: Schlemm’s Canal and Collector Channels as Therapeutic Targets. In Innovations in Glaucoma Surgery, Samples JR and Ahmed I eds. Chapter 1, page 3 – 25, Springer New York, 2014.
Allingham RR, de Kater AW, Ethier CR. Schlemm’s canal and primary open angle glaucoma: correlation between Schlemm’s canal dimensions and outflow facility. Exp Eye Research 1996;62:101 – 10
Maepea O, Bill A. Pressures in the juxtacanalicular tissue and Schlemm’s canal in monkeys. Exp Eye Res1992;54:879 – 883.
The iTrack™ canaloplasty microcatheter is the only device indicated for viscodilation in the treatment of open-angle glaucoma.INDICATIONS: The iTrack™ canaloplasty microcatheter has been cleared for the indication of fluid infusion and aspiration during surgery, and for catheterization and viscodilation of Schlemm’s canal to reduce intraocular pressure in adult patients with open-angle glaucoma. CONTRAINDICATIONS: The iTrack™ canaloplasty microcatheter is not intended to be used for catheterization and viscodilation of Schlemm’s canal to reduce intraocular pressure in eyes of patients with the following conditions: neovascular glaucoma; angle closure glaucoma; and, previous surgery with resultant scarring of Schlemm’s canal. ADVERSE EVENTS: Possible adverse events with the use of the iTrack™ canaloplasty microcatheter include, but are not limited to: hyphema, elevated IOP, Descemet’s membrane detachment, shallow or flat anterior chamber, hypotony, trabecular meshwork rupture, choroidal effusion, Peripheral Anterior Synechiae (PAS) and iris prolapse. WARNINGS: The iTrack™ canaloplasty microcatheter is intended for one time use only. DO NOT re-sterilize and/or reuse, as this can compromise device performance and increase the risk of cross contamination due to inappropriate reprocessing. PRECAUTIONS: The iTrack™ canaloplasty microcatheter should be used only by physicians trained in ophthalmic surgery. Knowledge of surgical techniques, proper use of the surgical instruments, and post-operative patient management are considerations essential to a successful outcome.