iStent inject W is a micro-invasive glaucoma operation that implants two 360-micron titanium stents through the eye's drainage meshwork into Schlemm's canal, restoring natural aqueous outflow and lowering intra-ocular pressure by around 20–30%. It is most commonly done at the same time as cataract surgery and is one of the lowest-risk ways to reduce both pressure and reliance on glaucoma drops.
What is iStent MIGS?
In open-angle glaucoma, fluid drains too slowly through the trabecular meshwork, raising pressure inside the eye and threatening the optic nerve. The iStent inject W bypasses the blockage: two tiny heparin-coated titanium stents are placed across the meshwork, opening a direct channel into Schlemm's canal so fluid can drain naturally again. The stents are invisible, stay in permanently and do not change your prescription.
iStent is a sensible first surgical step for mild-to-moderate open-angle glaucoma, pseudoexfoliation and pigmentary glaucoma, especially when you are already having cataract surgery. It is supported by the FDA pivotal trial and long-term real-world data. Learn more about glaucoma as a condition.
Your options
If a stronger pressure reduction is needed, higher-tier options include the PreserFlo MicroShunt, XEN gel stent and the Paul glaucoma tube implant. iStent can also be combined with a refractive lens exchange.
What happens during surgery
iStent is performed under local anaesthetic as a day case, usually taking only a few extra minutes when added to cataract surgery. Through the same tiny incision, and using a microscope-mounted gonioscopy lens to view the drainage angle, the surgeon implants the two stents into the trabecular meshwork. There are no stitches and nothing is visible afterwards.
Accurate placement under direct view is what makes the procedure effective and safe, which is why an experienced consultant glaucoma surgeon matters more than the headline price.
Wondering whether iStent could reduce your drops? A glaucoma assessment will tell you.
Book a glaucoma consultationRecovery and aftercare
First 24–48 hours
The eye may feel a little gritty and tender, easily managed with simple pain relief. You use prescribed drops and avoid rubbing the eye.
First week
Most people reach driving-standard vision within 24–72 hours of combined surgery and return to office work in 1–3 days. Air travel is fine from 24–48 hours — there is no gas bubble.
Ongoing
Your consultant checks the pressure and adjusts or stops drops over follow-up visits. The stents are permanent, with durable pressure reduction shown at 5–7 years.
How much does iStent cost?
Standalone iStent inject W is typically £3,000–£4,500 per eye. Combined with private cataract surgery — the commonest route — the all-inclusive fee is £4,500–£6,500 per eye, covering the consultant, the device, the lens implant, theatre, anaesthetist, drops and 12-month follow-up. Most major insurers cover iStent combined with medically indicated cataract surgery with pre-authorisation. See the full price list or request a personalised quote below.
iStent MIGS FAQs
How much does private iStent surgery cost?
Standalone iStent inject W is typically £3,000–£4,500 per eye. Combined with private cataract surgery — the commonest UK route — the all-inclusive fee is £4,500–£6,500 per eye, covering the consultant glaucoma surgeon, the iStent device, the lens implant, theatre, anaesthetist, drops and 12-month follow-up.
Will iStent get me off my glaucoma drops?
After combined cataract surgery and iStent, around 60–70% of patients with mild-to-moderate open-angle or pseudoexfoliation glaucoma are off all glaucoma drops at 12 months, though some still need one drop. Standalone iStent typically lowers eye pressure by 20–30% and lets your consultant simplify your drop regimen.
How does iStent compare to SLT laser and other MIGS?
SLT laser is usually offered first and lowers pressure for one to five years. iStent is a more durable option that combines naturally with cataract surgery and gives similar or slightly greater pressure reduction with higher medication-freedom rates. The Hydrus Microstent is an alternative trabecular device; your surgeon will recommend the best step for your glaucoma.
Is iStent surgery painful, and is it safe?
The procedure is performed under local anaesthetic, so you feel pressure but not pain. It is one of the lowest-risk glaucoma operations. The stents are left in place permanently, late blockage is rare, and durable pressure reduction has been shown at five to seven years.
When can I drive, work and fly after iStent?
Most people reach driving-standard vision within 24–72 hours of combined surgery, or 24 hours after standalone iStent, and return to office work in one to three days. Air travel is fine from 24–48 hours because there is no gas bubble in the eye, unlike retinal-detachment surgery.
Does insurance or the NHS cover iStent?
Major insurers including Bupa, AXA Health, Aviva, Vitality and WPA cover iStent combined with medically indicated cataract surgery in 2026 with pre-authorisation. Standalone iStent for ocular hypertension or mild glaucoma is usually self-pay. The NHS funds combined cataract-iStent surgery at commissioned trusts; the private route is chosen for speed, drop intolerance or consultant continuity.