woman leaning out of car window, enjoying life, free of glaucoma eye drops after istent surgery


Implanted during cataract surgery, or by itself, the iStent can help reduce your eye pressure and may reduce your need for glaucoma medication

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Small procedure. Big results.

Take advantage of what the world's smallest medical device can bring to your life.

Close up picture of a human eye showing the iris and pupil

What is glaucoma?

Glaucoma is a group of eye diseases commonly caused by an increased pressure inside the eye caused by a buildup of excess fluid. Treatment is aimed at lowering pressure to prevent further vision loss.

Diagram comparing a normal eye and an eye with glaucoma

Understanding glaucoma

Normal eye

In a healthy eye, a fluid called aqueous flows freely throughout the eye and travels through an internal drainage system.


If the drainage system is blocked or partially obstructed, the natural pressure in your eye may increase. When eye pressure becomes too high, the optic nerve can become damaged causing blurred vision, and if left untreated, vision loss or blindness. 

Senior Caucasian man inserting eye-drops

Are you tired of eye drops?

The iStent inject is a new therapy designed for people with glaucoma. It has been proven in global clinical trials to lower eye pressure, and in some patients, eliminate the need for glaucoma medication.

In a pivotal clinical trial of iStent inject implanted at the time of cataract surgery, it was observed that 84% of patients were medication-free at 23 months.

Introducing iStent inject

Picture of iStent inject W, a treatment for lowering eye pressure and the need for medications in glaucoma

What is the iStent inject?

The iStent inject is the smallest known implant in the human body that is inserted at the time of cataract surgery, or by itself, to treat glaucoma. This less invasive approach allows for fewer complications and faster healing times than traditional glaucoma surgery.

How does the iStent inject work?

iStent inject works like stents used to prevent heart attacks or strokes. When vessels get clogged, a stent opens them up to increase the flow of fluid. While iStent inject is a highly innovative technology, how it works is elegantly simple.

Talk to Dr Nathan Kerr to see if iStent inject is right for you.
  1. Designed to lower eye pressure

    Over time, your eye's natural drainage system gets clogged.

  2. Creating a permanent channel

    iStent inject creates a permanent channel through the primary blockage site (called the trabecular meshwork) to restore the eye's natural outflow.

  3. Treating the eye's natural drain

    iStent inject is designed to restore the natural outflow, lowering pressure within the eye.

Consider iStent inject

To manage your glaucoma

Is iStent inject right for me?

If you have mild-to-moderate glaucoma, you may benefit from reduction in eye pressure and/or a reduction in medication with iStent inject.

Technology has always played an important role in eye care. The iStent inject is an option for people with glaucoma who are experiencing side effects from eye drops and who want to reduce or eliminate their need for eye drops. 

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Dr Nathan Kerr
Melbourne Glaucoma and Cataract Surgeon

iStent inject

Advantages NEW
  • Lowers eye pressure
  • Minimally invasive
  • Fast recovery
  • May reduce need for eye drops
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Who may benefit from iStent inject?

It is necessary to first undergo an eye examination to determine if you are eligible for iStent inject. iStent inject is an effective surgical option for many glaucoma patients. If you fit into any of the following categories, you may be a candidate for the iStent inject:

Open-angle glaucoma

If you have primary open-angle, pseudoexfoliative, or pigmentary glaucoma.

Side effects from medication

If you are intolerant of glaucoma medications, or have difficulty taking them as prescribed.

Failed laser

If you have a history of failed laser trabeculoplasty.

Having cataract surgery

If you are about to have cataract surgery.

note The iStent inject, in addition for use in conjunction with cataract surgery, is also approved as a standalone therapy for the management of eye pressure.

Experienced iStent surgeon

Dr Nathan Kerr is one of Australia's leading specialists in minimally invasive cataract and glaucoma surgery

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Picture of Dr Nathan Kerr, Cataract Surgeon in Melbourne

Frequently asked questions

Discover how iStent inject could help treat your glaucoma.

What is iStent inject?

The iStent inject is a tiny device that is inserted into the natural drainage channel of the eye to help lower eye pressure and reduce the need for medications. It is so small you will not see or feel it after the procedure. The iStent is made of surgical-grade titanium so it won’t be rejected by the body. It will not set off airport scanners and is safe if you need to have an MRI scan.

How does iStent inject work?

Glaucoma is most commonly associated with a buildup of fluid pressure inside the eye. This build up of fluid pressure is caused by a blockage of the natural drainage channel of the eye. iStent inject creates two permanent openings in the natural drainage channel of the eye, bypassing the blockage, helping to drain fluid and reduce eye pressure. 

Who is suitable for iStent inject?

The iStent is suitable for patients with mild to moderate open-angle glaucoma who are going to have cataract surgery and wish to reduce their need for glaucoma medications. The iStent is not designed for advanced glaucoma or where the natural drainage system of the eye is damaged.

What are the benefits of iStent inject?

The iStent may help reduce eye pressure and the need for eye drops medications in patients with mild to moderate glaucoma who require cataract surgery. iStent insertion is faster, more straightforward, and less invasive than traditional operations for glaucoma.

In a large clinical trial, two-thirds of iStent patients remained medication-free while achieving an eye pressure reduction of 20% compared to only half of patients who underwent cataract surgery alone. In a UK study, eye pressure was 20% lower at 3 years after iStent insertion.

However, the eye pressure lowering effect of iStent insertion may reduce over time and you may need to resume using glaucoma medications. 

The iStent will not cure your glaucoma, reverse any damage already caused by glaucoma, or bring back any lost vision. 

What does the iStent inject operation involve?

The operation is usually performed under a local anaesthetic, meaning that you are awake but your eye is numb so you will not feel anything. Your eye will be numbed with eye drops and then a small injection will be given around your eye. The injection may cause a pressure sensation and brief discomfort. You will have the option of requesting light sedation. The local anaesthetic takes several hours to wear off and may affect your vision during this time.

iStent inject insertion takes only 5 – 10 minutes and is performed either at the end or the beginning of cataract surgery. The iStent inject is inserted into the natural drainage channel of the eye with an injector via a tiny incision.

At the end of the procedure your operated eye will be padded and covered with an eye shield. If your unoperated eye does not see well, your operated eye may not be padded and instead covered with a clear plastic shield.

You will usually be able to go home the same day as your operation. Most patients will need to be examined in the first week after surgery.

How soon will I recover after iStent inject?

Following surgery your eye may be slightly blood shot and swollen for a few days. Your vision may also be blurry for 1 – 2 weeks after the procedure. You may read and watch television; these activities will not harm your eye.

You will be given eye drops to prevent inflammation after the procedure.

The iStent should work straight away to lower your eye pressure, however you may still need to continue some glaucoma medication in the operated eye. You need to follow your doctor’s instruction. Any drops you use in your other eye must be continued as normal.
As with all eye surgery, you should avoid strenuous activity for the first month including swimming, tennis, jogging, and contact sports. Most people take 1 – 2 weeks off work after surgery, however the length of time will depend on the nature of your work.

You should avoid wearing eye make-up for approximately 4 weeks after surgery.

You will be asked to wear a shield over your eye at night for the first week or so, to prevent accidental injury to your eye whilst you are asleep.

It is safe to fly after surgery, however you will need to be seen regularly by your surgeon in the early post-operative period.

What will my eye look like after iStent inject surgery?

After surgery, your eye may be red for a few days to weeks but will then look normal. You will not be able to see or feel the iStent.  

What are the risks?

It is normal for there to be a small amount of bleeding inside the eye during the operation but this resolves within a few days. There is a risk the stent could become blocked or come out of position, however this is rare.

In some cases the iStent inject may not lower eye pressure or its effect may wear off with time. If the iStent fails to lower your eye pressure it will not create any additional harm to your eye. However, you may need to restart your glaucoma medications or have further procedures to control your eye pressure.

Are there any alternatives?

The Hydrus, iTrack, and XEN are alternative minimally invasive procedures that can be performed at the time of cataract surgery to lower eye pressure in patients with primary open angle glaucoma. Non-surgical alternatives include continuing to use eye drops to lower eye pressure or a laser procedure called selective laser trabeculoplasty.

If you liked this page, please share it on social media to let people with glaucoma know about iStent.

See Dr Nathan Kerr

Dr Kerr has been performing iStent procedures since 2016 and is one of Australia's most experienced MIGS surgeons. 

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Find out if iStent inject is right for you