Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness, with more than 64 million people diagnosed worldwide, among them 3 million Americans.1 Traditionally, we ophthalmologists have relied heavily on topical medication, laser therapy, and surgery to help protect our patients against this so-called “silent thief of sight.”
However, an exciting paradigm shift is underway with the emergence of interventional glaucoma. This innovative, proactive approach started with stand-alone, micro-invasive glaucoma surgery (MIGS) more than a decade ago and continues to revolutionize the way we combat POAG. Interventional glaucoma has reduced medication burden and improved quality of life for patients, and has delayed—and potentially even prevented—the need for more invasive surgeries and progression to blindness.
Challenges of Conventional Methods
Historically, ophthalmologists have taken a reactive approach to glaucoma treatment, waiting until
patients showed signs of disease progression before prescribing topical, drop-based medications to re-duce their intraocular pressure (IOP). When initial drop therapy failed to control IOP adequately and progression was documented, we typically would add medications before eventually moving on to laser therapy or more invasive surgeries, such as trabeculectomy and tube-shunt implantation.
This stepwise approach has limitations. Medication requires strict patient adherence, but we know that an average of 60% of patients fail to adhere to their drop regimen, which can include instilling as many as three different drops multiple times a day.2 Drops also are accompanied by side effects, such as dry eye disease, atrophy of the fat pads around the eyelids, chronic hyperemia, and meibomian gland dysfunction.
Also, trabeculectomy and tube-shunt implantation carry risks of adverse events and complications, including infection, hypotony, bleb-related issues, and corneal decompensation.3 On top of all that, most patients inevitably experience disease progression, highlighting the need for alternative approaches that can be implemented in early stages of the disease to preserve vision for longer periods of time.
The Emergence of Interventional Glaucoma Treatment
Enter interventional glaucoma. Despite the tendency among many specialists to remain loyal to traditional treatment approaches, the tide is turning toward standalone MIGS and micro-invasive technologies for patients with glaucoma whose therapeutic target doesn’t warrant more invasive procedures.
A prime example is the iStent infinite® Trabecular Micro-Bypass System (Glaukos), the only MIGS device designed and FDA-cleared for standalone treatment of patients with POAG in whom previous medical and surgical treatment has failed.4 Designed to bypass the trabecular meshwork at the lower nasal quadrant through a small incision in the cornea, the device consists of three 360-micron stents that take up just 3% of the angle to facilitate aqueous drainage through the trabecular meshwork and dramatically lower IOP.
The pivotal study published in 2023 by Sarkisian, et al., has demonstrated the efficacy and safety of the iStent infinite®, with significant reductions in IOP and medication dependence observed postoperatively.4 The multicenter trial involving patients with mild to moderate glaucoma showed a mean reduction in IOP of 33% at 12 months post-implantation. The study also found that a significant proportion of patients were able to reduce their dependence on topical glaucoma medications, thereby improving treatment adherence and reducing medication-related side effects.4
Giving Patients Proactive Options
So why do so many of us speak about how great MIGS is, but don’t make the most of it? Much of this comes down to the belief that drops are just easy. It’s easier
to write a prescription and hand it to the patient. The patient may go to the pharmacy and get it filled, but whether or not they use it is questionable. Market Scope surveyed U.S. ophthalmologists and found that 60% still write a drop prescription before they recommend a procedural intervention.5 This shows that we’re not there yet.
I have a longtime patient, a woman, who had prior cataract surgery when MIGS was not available. She
had previously undergone selective laser trabeculo-plasty, but she was still on multiple drops and had hyperemia and dryness. This was all significantly affecting her quality of life.
I wanted to get her IOP down further, but she had failed previous therapies and was on maximum tolerated medical therapy (MTMT), so I placed the iStent infinite. Now she’s on no medication, her eyes have cleared up, and she’s doing great. Considering how much patients struggle with POAG over time, to be able to lessen the burden on them is a big win.
Interventional glaucoma represents a significant advancement in the way we manage the disease. We no longer have to wait until a patient loses more vision. With tools like the iStent infinite, we now have more proactive options and can intervene earlier to preserve their vision—and quality of life—longer than ever before.*
*Individual results may vary.
Deborah Gess Ristvedt, DO, a board-certified ophthalmologist, practices with Vance Thompson Vision in Alexandria, Minn. She specializes in cataract surgery, micro-invasive glaucoma surgery, and oculo- plastics. She is a consultant for Allergan, BVI, Glaukos, Johnson & Johnson Vision, RxSight, and Sight Sciences.
REFERENCES
Tham YC, Li X, Wong TY, Quigley HA, Aung T, Cheng CY. Global prevalence of glaucoma and projections of glaucoma burden through 2040: A systematic review and meta-analysis. Ophthalmology. 2014;121(11):2081-2090.
Moore SG, Richter G, Modjtahedi BS. Factors affecting glaucoma medication adherence and interventions to improve adherence: A narrative review. Ophthalmol Ther. 2023;12(6):2863-2880.
Gedde SJ, Herndon LW, Brandt JD, et al. Postoperative complications in the tube versus trabeculectomy (TVT) study during five years of follow-up. Am J Ophthalmol. 2012;153(5):804-814.e1.
Sarkisian SR Jr, Grover DS, Gallardo MJ, et al. Effectiveness and safety of iStent infinite trabecular micro-bypass for uncontrolled glaucoma. J Glaucoma. 2023;32(1):9-18.
Market Scope. Glaukos Custom Survey Report: Interventional Glaucoma Survey. March 2023.
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IMPORTANT SAFETY INFORMATION:
iSTENT INFINITE® INDICATIONS FOR USE. The iStent infinite® Trabecular Micro-Bypass System Model iS3 is an implantable device intended to reduce the intraocular pressure (IOP) of the eye. It is indicated for use in adult patients with primary open-angle glaucoma in whom previous medical and surgical treatment has failed. CONTRAINDICATIONS. The iStent infinite is contraindicated in eyes with angle-closure glaucoma where the angle has not been surgically opened, acute traumatic, malignant, active uveitic, or active neovascular glaucoma, discernible congenital anomalies of the anterior chamber (AC) angle, retrobulbar tumor, thyroid eye disease, or Sturge-Weber Syndrome or any other type of condition that may cause elevated episcleral venous pressure. WARNINGS. Gonioscopy should be performed prior to surgery to exclude congenital anomalies of the angle, PAS, rubeosis, or conditions that would prohibit adequate visualization that could lead to improper placement of the stent and pose a hazard. MRI INFORMATION. The iStent infinite is MRConditional, i.e., the device is safe for use in a specified MR environment under specified conditions; please see Directions for Use (DFU) label for details. PRECAUTIONS. The surgeon should monitor the patient postoperatively for proper maintenance of IOP. Three out of 61 participants (4.9%) in the pivotal clinical trial were phakic. Therefore, there is insufficient evidence to determine whether the clinical performance of the device may be different in those who are phakic versus in those who are pseudophakic. ADVERSE EVENTS. The most common postoperative adverse events reported in the iStent infinite pivotal trial included IOP increase ≥ 10 mmHg vs. baseline IOP (8.2%), loss of BSCVA ≥ 2 lines (11.5%), ocular surface disease (11.5%), perioperative inflammation (6.6%) and visual field loss ≥ 2.5 dB (6.6%). CAUTION: Federal law restricts this device to sale by, or on the order of, a physician. Please see DFU for a complete list of contraindications, warnings, precautions, and adverse events.
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