Health condition · Clinically reviewed
Glaucoma, silent optic nerve damage — screening, drops, laser and modern MIGS surgery.
Progressive optic nerve damage — usually painless until late. Regular eye tests catch it; drops, selective laser trabeculoplasty and MIGS all reduce IOP and preserve vision.
Why trust this guide
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Clinically reviewed
Written by our editorial team and reviewed by a registered UK clinician before publication.
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Sourced, not summarised
Every claim is checked against NICE, the Royal College of Ophthalmologists or a peer-reviewed source you can see at the end.
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Updated for 2026
Reflects current UK guidance on SLT-first pathways, drop escalation and modern MIGS surgery.
Key facts
Glaucoma at a glance.
The essentials, in plain English — what it is, which type is which, and how it’s treated in the UK today.
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What it is
A progressive optic neuropathy with characteristic visual field loss, usually — but not always — linked to raised intraocular pressure.
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Most common form
Primary open-angle glaucoma is the commonest type in the UK — usually painless and silent until late.
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Emergency form
Acute angle-closure glaucoma is a same-day emergency — painful red eye, halos and vomiting.
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First-line treatment
Selective laser trabeculoplasty (SLT) is now first-line in NICE NG81 for most open-angle glaucoma and ocular hypertension.
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Modern surgery
Minimally-invasive glaucoma surgery (MIGS) — iStent, Hydrus, Preserflo — has expanded options beyond trabeculectomy.
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Prevention
Regular eye tests are essential — most sight loss from glaucoma is preventable if caught early.
Why this guide matters
Sight loss you can prevent — if you catch it.
Glaucoma is silent, treatable and hereditary. The three points below shape everything else on this page.
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Silent until it isn’t
Open-angle glaucoma damages peripheral vision first — you often don’t notice until half the nerve fibres are gone.
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SLT changed the pathway
A single 10-minute laser is now first-line for most people — controlling pressure without daily drops.
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Family history is a real risk
A parent or sibling with glaucoma raises your risk four-to-ten-fold. Sight tests from 40 are essential.
How the diagnosis is made
From sight test to a clear plan.
The steps a UK optometrist and hospital eye service will normally follow, in order — so you know what to expect and why.
Phase 1 · Detecting
Optometry, fields and OCT pick up early signs
Phase 2 · Confirming
Gonioscopy and disc assessment stage the disease
Phase 3 · Managing
Ophthalmology treatment and family screening
- 01
Detecting
Optometry with IOP measurement
Routine sight test picks up raised intraocular pressure or a suspicious optic disc.
- 02
Detecting
Visual field testing (HVF)
Humphrey visual field maps early peripheral loss — the signature of glaucoma.
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Detecting
OCT of retinal nerve fibre layer
A quick, painless scan that measures nerve-fibre thickness around the optic disc.
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Confirming
Gonioscopy (angle assessment)
Special lens exam to see whether the drainage angle is open or closed.
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Confirming
Fundoscopy (cup:disc ratio)
Direct view of the optic nerve head — cupping is the classic sign.
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Managing
Ophthalmology confirmation
Hospital eye service confirms the diagnosis and stages severity before treatment.
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Managing
Family cascade screening
First-degree relatives are advised to have an eye test — glaucoma runs in families.
Typical timeline: 4–12 weeks from optometry referral to a settled treatment plan.
Symptoms
What glaucoma actually feels like.
Open-angle usually feels like nothing. Angle-closure feels like an emergency. Here’s what to watch for and when to seek urgent care.
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Silent (open-angle)
Open-angle glaucoma usually has no symptoms until peripheral vision is already lost. Regular sight tests are the only reliable way to find it.
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Painful red eye (angle-closure)
Sudden severe eye pain with a red, hard eye — a hallmark of acute angle-closure glaucoma.
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Halos around lights
Rainbow halos, especially at night, can precede or accompany an angle-closure attack.
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Reduced peripheral vision
Tunnel vision or bumping into things — a late sign of open-angle glaucoma.
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Nausea and vomiting
Angle-closure attacks often cause systemic symptoms — nausea, vomiting and headache alongside the eye pain.
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Family history
A first-degree relative with glaucoma raises your risk substantially — cascade screening is offered.
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African / Asian descent
People of African descent are at higher risk of open-angle glaucoma; East Asian descent raises angle-closure risk.
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When to seek urgent care
Acute painful red eye with halos and vomiting — call 999 or attend A&E. Sight loss from angle-closure is preventable only if treated within hours.
Treatment
How glaucoma is treated in the UK.
Laser first, drops where needed, surgery when required — what each option does and how it fits into modern UK practice.
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Selective laser trabeculoplasty (SLT)
First-line in NICE NG81 for most open-angle glaucoma and ocular hypertension — a quick outpatient laser to the trabecular meshwork.
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Prostaglandin analogue drops
Latanoprost and similar drops are the mainstay medical therapy — once-daily, well tolerated, powerful IOP lowering.
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Beta-blocker drops
Timolol and others reduce aqueous production — often used as an add-on when prostaglandins alone aren’t enough.
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Carbonic anhydrase inhibitors
Dorzolamide or brinzolamide drops — another add-on that reduces fluid production inside the eye.
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Alpha-agonist drops
Brimonidine lowers pressure by reducing production and increasing outflow — useful in escalation.
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Trabeculectomy
Traditional filtering surgery creating a new drainage channel — very effective, still the reference standard for advanced disease.
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Tube shunt (drainage implant)
A small tube guides aqueous to a reservoir under the conjunctiva — used when trabeculectomy is unlikely to succeed.
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MIGS (iStent, Hydrus, Preserflo)
Minimally-invasive glaucoma surgery — micro-implants and micro-shunts with faster recovery and fewer complications than trabeculectomy.
What this guide is based on
The sources behind every claim on this page.
UK national guidance and specialist society standards, current at the time of last review.
Key references
Guidelines and standards we relied on.
A quiet reminder
This guide is for information, not medical advice.
Your optometrist and ophthalmologist know your history and can tell you which parts apply to you. If in doubt, get your eyes checked.
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National Institute for Health and Care Excellence (NICE). Glaucoma: diagnosis and management (NG81).
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Royal College of Ophthalmologists. Commissioning guidance and clinical standards for glaucoma.
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European Glaucoma Society. Terminology and Guidelines for Glaucoma (5th edition).
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International Glaucoma Association (now Glaucoma UK). Patient information and support standards.
Red flags
When glaucoma becomes an emergency.
Most glaucoma is a slow burn. These are the situations where it stops being slow — and you should act today.
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Acute angle-closure glaucoma
Painful red eye, halos around lights, nausea and vomiting — a sight-threatening emergency. Call 999 or attend A&E.
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Sudden vision loss
Any sudden loss of vision — partial or complete — needs same-day ophthalmology assessment.
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Post-op leak or infection
Increasing pain, redness or blurred vision after glaucoma surgery — contact your surgeon urgently.
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Malignant glaucoma
A rare post-operative complication with a shallow anterior chamber and rising pressure — needs urgent specialist care.
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Neovascular glaucoma
New vessel growth on the iris — often after diabetic eye disease or retinal vein occlusion. Refer urgently.
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Steroid-induced IOP rise
Long-term topical, inhaled or oral steroids can raise intraocular pressure — monitor and review.
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Congenital glaucoma
Cloudy or enlarged eyes, watering and light sensitivity in a baby — urgent paediatric ophthalmology referral.
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Uveitic glaucoma
Raised pressure with inflammation inside the eye — needs joint uveitis and glaucoma management.
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Post-SLT / MIGS complications
Pressure spike, persistent inflammation or vision change after laser or MIGS surgery — contact the eye unit.
Living with it
A long-term condition, but a very manageable one.
Four things that make the biggest difference day to day — habits, monitoring, technique and reviews.
A quiet reminder
Consistency beats intensity, every time.
Small, steady changes — kept up for years — do more than a heroic month that doesn’t last.
- 01 Daily habits
Drops on time, every day
Consistency matters more than perfection — set a phone reminder and link drops to a daily habit like brushing your teeth.
- 02 Monitoring
Fields and OCT tell the story
Regular visual fields and OCT scans track progression — not one-off pressure readings.
- 03 Medication
Technique beats brand
Punctal occlusion (closing the tear duct for a minute after drops) reduces side effects and improves absorption.
- 04 Reviews
Stable is a win
The goal isn’t perfect pressure — it’s stable fields and nerves over years. Attend every review.
Frequently asked
Everything we get asked about glaucoma.
Quick answers on SLT, drops, MIGS surgery, family risk and when to worry.
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Is glaucoma always caused by high eye pressure?
No — normal-tension glaucoma damages the optic nerve at pressures within the normal range. Treatment still focuses on lowering pressure further, because that is what has been shown to slow progression.
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Can glaucoma be cured?
No — but it can be controlled. Modern SLT, drops and MIGS surgery can stabilise the disease for decades if started early.
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How often should I have an eye test?
At least every two years, or annually from age 40 if a first-degree relative has glaucoma or you are of African descent. NHS sight tests are free in these groups.
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What is SLT and why is it now first-line?
Selective laser trabeculoplasty is a quick outpatient laser to the drainage meshwork. NICE NG81 made it first-line in 2022 because the LiGHT trial showed better long-term control and fewer drops than starting with medication.
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Are eye drops for life?
Often yes, though SLT can defer or reduce the need for drops. Drops work only while you use them — stopping causes pressure to rebound.
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What does MIGS actually mean?
Minimally-invasive glaucoma surgery — a family of tiny implants (iStent, Hydrus) and micro-shunts (Preserflo) that lower pressure with faster recovery and fewer complications than traditional trabeculectomy.
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