Clinical Data

iStent inject® W Clinical Data

Trabecular micro-bypass technology developed by Glaukos has been studied extensively around the world and its efficacy has been demonstrated in more than 200 peer-reviewed articles, 20 years of clinical use, and over one million eyes.

The implantation of two trabecular bypass stents – without the benefit of cataract surgery – has been shown in prospective clinical trials to both lower IOP to <15 mm Hg and reduce medication burden via a unique two stent approach:

Independent Clinical Study Results

Additional independent, long-term studies of Glaukos trabecular micro-bypass technology suggest that results are maintained several years after the procedure.

Study (duration) # of Subjects (at endpoint) Post-Op Mean IOP (mmHG) % IOP Reduction % Medication Reduction
Study (duration) Guedes1 (12M) # of Subjects (at endpoint) 23 Post-Op Mean IOP (mmHG) 13.1 % IOP Reduction 19.1% % Medication Reduction 94.1%
Study (duration) Clement2 (12M) # of Subjects (at endpoint) 165 Post-Op Mean IOP (mmHG) 14.0 % IOP Reduction 23.2% % Medication Reduction 71.5%
Study (duration) Manning3 (12M) # of Subjects (at endpoint) 70 Post-Op Mean IOP (mmHG) 14.4 % IOP Reduction 29.4% % Medication Reduction 94.7%
Study (duration) Hengerer4 (84M) # of Subjects (at endpoint) 125 Post-Op Mean IOP (mmHG) 14.1 % IOP Reduction 40.0% % Medication Reduction 59.0%
Study (duration) Arriola-Villalobos5 (48M) # of Subjects (at endpoint) 20 Post-Op Mean IOP (mmHG) 16.25 % IOP Reduction 36.92% % Medication Reduction 42.3%

Can Reduce Intraocular Pressure (IOP) and
Medication Burden

iStent inject® W builds on the trabecular micro-bypass technology of iStent inject®, which has been proven effective in numerous studies in lowering IOP and reducing medication burden.

In one notable consecutive case study of iStent inject® involving multiple international surgeons, average medication usage was reduced from 1.0 to 0.1 at 12 months.6

Long-Term IOP Reduction5

Chart showing average medication usage was reduced from 1.0 to 0.1 at 12 months.

Another study conducted by multiple international surgeons demonstrated a mean IOP reduction of 47% vs. medicated screening at 18 months, finding that stents alone lowered IOP 5.1 mmHg from medicated screening.7

Line chart showing the mean IOP over time with a mean IOP reduction of 34% as compared to the medicated screening.

In a consecutive case series with three-year follow-up, mean IOP was 14.3 ± 1.7 mm Hg, representing a 37% reduction from preoperative medicated mean IOP of 22.6 ± 6.2 mm Hg, and 100% of eyes had an IOP ≤ 18 mm Hg.8

A bar graph showing sustained medication reduction: mean medication use was decreased from 2.5 to 0.8 medications at three years, a 68% reduction. Reduction key: dark green is 0 Med, green is 1 Med, dark blue is 2 Med, bright blue is 3 Med, blue is 4+ Med.

In the same consecutive case series, mean medication use was decreased from 2.5 to 0.8 medications at three years, a 68% reduction. And 74% of eyes were using 0 or 1 medication as compared to 21% preoperatively.8

Medication reduction is subject to the discretion of the physician.

  1. Guedes RAP, Gravina DM, Lake JC, Guedes VMP, Chaoubah A. Intermediate results of iStent® or iStent inject® implantation combined with cataract surgery in a real-world setting: a longitudinal retrospective study. Ophthalmol Ther. March 2019;8(1):87-100.
  2. Clement CI, Howes F, Ioannidis AS, Shiu M, Manning D. One-year outcomes following implantation of second-generation trabecular micro-bypass stents in conjunction with cataract surgery for various types of glaucoma or ocular hypertension: multicenter, multi-surgeon study. Clin Ophthalmol. 2019:13;491-499.
  3. Manning D. Real-world case series of iStent® or iStent inject® trabecular micro-bypass stents combined with cataract surgery. Ophthalmology & Therapy. 2019. doi:
  4. Hengerer FH, Auffarth G, Conrad-Hengerer I. Sustained 7-year glaucoma control after second-generation trabecular micro-bypass with or without cataract surgery. Abstract presented at: Annual Meeting of the American Society of Cataract and Refractive Surgery; May 5-8, 2023; San Diego, CA.
  5. Arriola-Villalobos P, Martinez-de-la-Casa JM, Diaz-Valle D, et al. Glaukos iStent inject® trabecular micro-bypass implantation associated with cataract surgery in patients with coexisting cataract and open-angle glaucoma or ocular hypertension: a long-term study. J Ophthalmology. 2016;1-7.
  6. Donnenfeld ED, Solomon KD, Voskanyan L, et al. A prospective 3-year follow-up trial of implantation of two trabecular microbypass stents in open-angle glaucoma. Clin Opth. 2015;9:2057-2065.
  7. Samuelson TW. Outcomes of MIGS with Trabecular Micro-Bypass Stents and Prostaglandin in Open-Angle Glaucoma Subjects. Presented at the 2013 American Society of Cataract and Refractive Surgery Annual Meeting; April 19-23, 2013; San Francisco, California, USA.
  8. Hengerer FH. Personal Experience with Second-Generation Trabecular Micro-Bypass Stents in Combination with Cataract Surgery in Patients with Glaucoma: 3-Year Follow-up. ASCRS 2018 Presentation.

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iStent inject® W Important Safety Information

Indications for Use

The iStent inject® W is intended to reduce intraocular pressure safely and effectively in patients diagnosed with primary open-angle glaucoma, pseudo-exfoliative glaucoma or pigmentary glaucoma. The iStent inject® W, can deliver two (2) stents on a single pass, through a single incision. The implant is designed to stent open a passage through the trabecular meshwork to allow for an increase in the facility of outflow and a subsequent reduction in intraocular pressure.

The device is safe and effective when implanted in combination with cataract surgery in those subjects who require intraocular pressure reduction and/or would benefit from glaucoma medication reduction. The device may also be implanted in patients who continue to have elevated intraocular pressure despite prior treatment with glaucoma medications and conventional glaucoma surgery.


The iStent inject® W System is contraindicated under the following circumstances or conditions:

  • In eyes with primary angle closure glaucoma, or secondary angle-closure glaucoma, including neovascular glaucoma, because the device would not be expected to work in such situations.
  • In patients with retrobulbar tumor, thyroid eye disease, Sturge-Weber Syndrome or any other type of condition that may cause elevated episcleral venous pressure.


  • For prescription use only.
  • This device has not been studied in patients with uveitic glaucoma.
  • Do not use the device if the Tyvek® lid has been opened or the packaging appears damaged. In such cases, the sterility of the device may be compromised.
  • Due to the sharpness of certain injector components (i.e. the insertion sleeve and trocar), care should be exercised to grasp the injector body. Dispose of device in a sharps container.
  • iStent inject® W is MR-Conditional; see MRI Information here.
  • Physician training is required prior to use of the iStent inject® W System.
  • Do not re-use the stent(s) or injector, as this may result in infection and/or intraocular inflammation, as well as occurrence of potential postoperative adverse events as shown below under “Potential Complications.”
  • There are no known compatibility issues with the iStent inject® W and other intraoperative devices (e.g., viscoelastics) or glaucoma medications.
  • Unused product & packaging may be disposed of in accordance with facility procedures. Implanted medical devices and contaminated products must be disposed of as medical waste.
  • The surgeon should monitor the patient postoperatively for proper maintenance of intraocular pressure. If intraocular pressure is not adequately maintained after surgery, the surgeon should consider an appropriate treatment regimen to reduce intraocular pressure.
  • Patients should be informed that placement of the stents, without concomitant cataract surgery in phakic patients, can enhance the formation or progression of cataract.

Adverse Events

Please refer to Directions For Use for additional adverse event information.


Please reference the Directions For Use labelling for a complete list of contraindications, warnings and adverse events.