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Consultant Ophthalmologist, Cataract & Refractive Surgeon
BMedSci BM BS MRCS MRCSEd MRCOpth FRCOphth MMedLaw PgD Cataract & Refractive Surgery

Glaukos iStent® for those of you who have glaucoma and cataract

If you have co-existent cataract and glaucoma then this could be the ideal option for you. Glaucoma is caused by obstruction/resistance to the drainage of the
clear fluid (aqueous) from inside the eye. As the eye in non-distensible (cannot stretch) any increase in the amount of fluid in the eye can send the pressure high and damage the optic nerve. The iStent is inserted at the time of cataract surgery and bypasses the area of resistance to fluid outflow. It aims to get the pressure down in the eye and hopefully allow us to reduce the number of (or even stop) your glaucoma eye drops.

This additional procedure extends the operation by only a few minutes and the benefits can be long lasting.

The iStent® is the smallest medical device that has ever been implanted in the human body

  • Approximately 1 mm in length
    • Size: 0.5 mm x 0.25 mm x 1.0 mm
    • Weight: approximately 60 µg
    • Snorkel bore diameter: 120 µm
  • Made of surgical grade nonferromagnetic titanium


iStent® Surgical Procedure

The iStent® is inserted through the clear, cornea cataract incision and can be performed under local or topical anesthesia.


The more technical stuff:

iStent® bypasses the trabecular meshwork in the infranasal locations

  • Maximizing outflow through Schlemm's canal
  • Reestablishing continuous, physiological outflow in the lower nasal quadrants
  • Increasing outflow due to the high presence of collector channel congregations[3, 5]

iStent® Maximizes Outflow Through One Opening


Reduce or Eliminate Medication with iStent®

Improve IOP control in more patients with iStent®

Percentage of Patients Who Sustained IOP ≤21 mm Hg without Medication Use


Prospective, randomized, multicenter study across 27 US sites, of 240 patients with cataract and mild to moderate glaucoma were treated with ocular antihypertensive medications at baseline. All patients were assigned to a postmedication washout period before undergoing cataract surgery or iStent® implantation plus cataract surgery.
At 12 months

  • 73% of patients who received iStent® remained medication free while sustaining target IOPs of ≤21 mm Hg versus only 50% of those who underwent cataract surgery alone (P<0.001)

Percentage of Patients who Sustained a ≥20% Reduction in IOP Without Medication Use


At 12 months

  • 67% of patients who received iStent® remained medication free while sustaining a mean IOP reduction of ≥20% versus only 48% who underwent cataract surgery alone (P<0.002)
  • 19% more patients who received iStent® sustained a ≥20% reduction in IOP without medication use versus cataract surgery alone


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2. Spiegel D, Garcia-Feijoo J, Garcia-Sanchez J, Lamielle H: Coexistent primary open-angle glaucoma and cataract: preliminary analysis of treatment by cataract surgery and the iStent trabecular micro-bypass stent. Adv Ther 2008, 25:453-464.
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