Glaucoma is a group of conditions that damage the optic nerve, most often caused by raised pressure inside the eye (intraocular pressure). It usually develops without symptoms, so it is frequently detected during a routine eye test. While sight already lost cannot be restored, treatment — eye drops, SLT laser from £950, or minimally invasive surgery (MIGS) — is highly effective at lowering pressure and preventing further damage.
What is glaucoma?
Glaucoma describes a group of eye conditions in which the optic nerve — the cable of more than a million fibres that carries images from your eye to your brain — becomes progressively damaged. In most cases this is linked to raised pressure inside the eye, caused by fluid (aqueous humour) not draining away as efficiently as it should.
The most common form, primary open-angle glaucoma, develops so gradually that peripheral (side) vision is lost first, often without the person noticing until the disease is advanced. Less commonly, acute angle-closure glaucoma comes on suddenly with a red, painful eye and is a medical emergency. Around 700,000 people in the UK are affected, and glaucoma remains one of the leading causes of preventable sight loss.
Symptoms of glaucoma
Chronic (open-angle) glaucoma is often called the “silent thief of sight” because it usually causes no pain and no early symptoms. When signs do appear, they may include:
- Patchy blind spots in your side or peripheral vision
- Tunnel vision in advanced stages
- Difficulty adjusting to low light or seeing in the dark
Acute angle-closure glaucoma is different and needs same-day care. Warning signs include sudden severe eye pain, a red eye, blurred vision, halos around lights, headache, and nausea or vomiting.
Worried about your eye pressure? A glaucoma assessment includes OCT optic-nerve imaging and visual field testing to detect damage early.
Book a glaucoma assessmentCauses & risk factors
Glaucoma develops when intraocular pressure damages the optic nerve, though some people develop nerve damage even with “normal” pressure (normal-tension glaucoma). Your risk is higher if you:
- Are over 40 — risk rises steadily with age
- Have a close relative with glaucoma — a parent or sibling raises your risk several-fold
- Are of African, Caribbean or Asian heritage
- Are very short-sighted (myopic) or very long-sighted
- Have diabetes or high blood pressure
- Have used steroid medication long-term
How glaucoma is diagnosed
Glaucoma is painless to test for and diagnosis combines several quick, non-invasive checks at a single consultant appointment:
- Tonometry — measures the pressure inside your eye.
- OCT imaging — a detailed scan of the optic nerve and retinal nerve-fibre layer to detect damage before vision is affected.
- Visual field test — maps your peripheral vision to find any blind spots.
- Gonioscopy — examines the eye’s drainage angle to identify the type of glaucoma.
- Pachymetry — measures corneal thickness, which affects pressure readings.
Treatment options
The goal of treatment is to lower eye pressure and protect the optic nerve. Treatment is tailored to the type and severity of your glaucoma — see our glaucoma treatment overview for full detail.
- Eye drops — usually the first-line treatment, lowering pressure by reducing fluid production or improving drainage.
- SLT laser — selective laser trabeculoplasty, a quick day-case treatment from £950 per eye that improves the eye’s natural drainage. See SLT laser pricing.
- Minimally invasive glaucoma surgery (MIGS) — tiny implants such as the iStent, Hydrus Microstent or Preserflo MicroShunt that lower pressure with a faster recovery than traditional surgery.