Private Kahook Dual Blade Goniotomy (MIGS) UK

Kahook Dual Blade (KDB) goniotomy is an implant-free MIGS procedure that uses a single-use, dual-edged microsurgical blade to excise a strip of the trabecular meshwork, lowering eye pressure by improving the eye's natural drainage. It suits mild-to-moderate open-angle glaucoma and is most often added to cataract surgery ("phaco-goniotomy"), though it can be done standalone. UK 2026 self-pay starts from £2,500 when combined with cataract surgery; standalone MIGS is typically £3,000–£4,500.

What is Kahook Dual Blade goniotomy?

The trabecular meshwork is a ring of drainage tissue in the angle of the eye. In open-angle glaucoma, this tissue becomes a bottleneck: fluid (aqueous humour) builds up, pressure rises, and the optic nerve is gradually damaged. The Kahook Dual Blade — made by New World Medical and CE-marked for UK use — is a precision instrument with two parallel cutting edges and a ramp that lifts and stretches the meshwork before its twin blades excise a clean strip of tissue rather than simply tearing or stretching it.

By removing this strip of resistant tissue, aqueous fluid can drain more freely into the eye's own collector channels (Schlemm's canal), lowering intraocular pressure. Crucially, KDB goniotomy is "stentless" — it leaves no device, stent or implant inside the eye. This sets it apart from stent-based MIGS such as the iStent or the Hydrus Microstent.

KDB goniotomy is part of the wider family of MIGS — minimally invasive glaucoma surgery — which aims to lower pressure with less tissue disruption, faster recovery and a better safety profile than traditional filtering surgery. It is best suited to mild-to-moderate disease. Advanced or refractory glaucoma usually needs a more powerful pressure-lowering operation such as trabeculectomy or a tube/microshunt.

How KDB goniotomy compares with other MIGS

All trabecular MIGS target the same drainage pathway, but they do it in different ways. Your surgeon will recommend the right option after gonioscopy and an assessment of your glaucoma severity, target pressure and whether you are also having cataract surgery.

KDB goniotomy

Excises tissue · implant-free. Removes a strip of trabecular meshwork to open the drainage pathway. No device left behind, so it keeps future surgical options open. Ideal for mild-to-moderate open-angle glaucoma, alone or with cataract surgery.

Stent MIGS (iStent / Hydrus)

Implants a device. A tiny titanium iStent or curved Hydrus scaffold is placed to bypass or hold open the meshwork. The implant stays permanently in the eye.

Canaloplasty (OMNI)

Reopens the canal. OMNI canaloplasty dilates Schlemm's canal with viscoelastic and can also perform a trabeculotomy — treating more of the drainage system in one device, again without leaving an implant.

Where pressure needs to be lower than trabecular MIGS can reliably achieve, subconjunctival options such as the PreserFlo MicroShunt or XEN gel stent create a new drainage route — these are a step up in both effect and risk. For early disease or before surgery, laser options like SLT may be appropriate. Our guide to glaucoma treatment options explains how drops, laser and MIGS fit together.

What happens during the procedure

KDB goniotomy is performed ab interno — from inside the eye, through the same micro-incision used for cataract surgery — so there is no external wound or stitch in most cases. It typically adds only a few minutes to the operation.

Anaesthesia. Local anaesthetic drops or injection numb the eye; you stay awake but feel no pain. Sedation is available if you are anxious.
Access. If combined with cataract surgery, the cloudy lens is removed and a lens implant placed first. The surgeon then uses the existing tiny incision.
Gonioscopy view. A special lens (gonioprism) and tilting of the microscope give a direct view of the drainage angle.
Goniotomy. The Kahook Dual Blade is advanced into the angle; its ramp lifts the trabecular meshwork and the dual edges excise a clean strip of tissue, opening the pathway to Schlemm's canal.
Finish. The instrument is withdrawn, any blood is irrigated, and the self-sealing incision usually needs no stitch. A shield is placed over the eye.

Wondering whether KDB goniotomy or another MIGS is right for your glaucoma? A consultation clarifies your options.

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Recovery and what to expect

Recovery is generally quick because the eye surface is barely disturbed. A short, blood-tinged blur in the first day or two is normal and expected — see the FAQs on hyphaema below.

Day of surgery

You go home the same day. Vision is often hazy and may show a faint red tinge from a small amount of blood in the eye (hyphaema). Wear the shield as advised.

First week

Use anti-inflammatory and antibiotic drops as prescribed. Avoid rubbing the eye, heavy lifting and swimming. Any hyphaema usually settles within days.

Weeks 2–6

Vision stabilises and pressure is monitored. Your surgeon reviews whether glaucoma drops can be reduced. An early, temporary pressure spike is checked for at follow-up.

Long term

Lifelong glaucoma monitoring continues. KDB can reduce — and sometimes eliminate — the need for some drops, but glaucoma is a chronic condition that still needs review.

Cost of KDB goniotomy in the UK

When KDB goniotomy is added to private cataract surgery ("phaco-goniotomy"), the goniotomy element typically starts from £2,500 above the cataract fee. As a standalone MIGS procedure it is usually £3,000–£4,500, depending on the clinic, surgeon and pre-operative assessment. Your quote covers the consultant's fee, the single-use Kahook Dual Blade, theatre time and routine follow-up.

Compare the wider range of glaucoma procedures on our private glaucoma surgery cost guide, or see all glaucoma treatments. Many patients combine this with cataract surgery in a single visit. Most major insurers cover MIGS where clinically indicated, and 0% finance is available for self-pay.

Frequently asked questions

Does KDB goniotomy leave an implant in my eye?

No. Kahook Dual Blade goniotomy is an implant-free, or "stentless", MIGS procedure. The blade excises a strip of trabecular meshwork tissue and is then removed — nothing is left inside the eye, unlike stent-based MIGS such as the iStent or Hydrus Microstent.

How is KDB different from an iStent or Hydrus?

The iStent and Hydrus are tiny permanent devices placed to bypass or hold open the trabecular meshwork. KDB goniotomy instead removes a strip of that meshwork to open the natural drainage pathway, leaving no implant behind. Removing rather than stenting tissue can keep future surgical options more open.

Who is suitable for KDB goniotomy?

It is best suited to people with mild-to-moderate open-angle glaucoma, very often those also having cataract surgery, where modest, safe pressure reduction is the goal. It is not designed for advanced or refractory glaucoma, where a more powerful operation such as trabeculectomy or a tube/microshunt may be needed.

Is bleeding in the eye normal afterwards?

Yes. A small amount of blood in the front of the eye (hyphaema) is common and expected after goniotomy because the drainage channels can briefly reflux blood. It usually causes a temporary red tinge and mild blur that settles within a few days, and your surgeon will check it at follow-up.

Can KDB goniotomy be done at the same time as cataract surgery?

Yes — this is one of its most common uses, often called "phaco-goniotomy". The cataract is removed and a lens implant placed first, then the goniotomy is performed through the same micro-incision, usually adding only a few minutes to the operation.

Will I be able to stop my glaucoma drops?

KDB goniotomy can reduce the number of glaucoma drops you need, and some patients are able to stop them, but results vary. Glaucoma is a lifelong condition, so ongoing monitoring continues regardless of how many drops you take afterwards.

What are the main risks?

KDB has a favourable safety profile, but possible effects include transient hyphaema (expected), a short-lived intraocular pressure spike, inflammation, and — less commonly — the procedure not lowering pressure enough, meaning further treatment is needed. Your surgeon will discuss your individual risks at consultation.

How much does KDB goniotomy cost in the UK?

For UK 2026 self-pay, KDB goniotomy combined with cataract surgery typically starts from £2,500 above the cataract fee. As a standalone MIGS procedure it is usually £3,000–£4,500. Most major insurers cover it where clinically indicated, and 0% finance is available.

Private Kahook Dual Blade goniotomy (MIGS)