A sudden painful red eye with halos around lights: acute glaucoma and why it means hospital today
Mum has a red, aching eye, lights with halos around them, a headache and she keeps vomiting. It looks like a migraine or a stomach upset, but it can be acute glaucoma. Here is why it means hospital today, who is more at risk, and how the family can lower the risk.
Go to the emergency department or call 999 now if a red eye comes with…
I see parents and grandparents for squint, cataract and everyday eye problems, I operate on squint and cataract, and I perform LASIK, SMILE and Presbyond for adults, so one family can keep one eye doctor. Family eye care Where I practise
- A sudden red, painful eye with blurred vision and halos around lights, with a headache, nausea or vomiting, can be an acute angle-closure glaucoma attack. The AAO calls it a true eye emergency, and the NHS says to call 999 or go to A&E.
- In Malaysia that means a hospital emergency department the same day, or 999. Do not wait for a clinic appointment, and do not drive yourself.
- The headache and vomiting can hide the eye: reviews describe attacks mistaken for gastroenteritis, and a woman with known migraine who had a head scan before the eye was checked.
- Older age, female sex, Asian and Chinese ancestry, long-sightedness and a family history raise the risk. Some medicines, named by class in the sources, can trigger an attack in a narrow eye.
- The hospital lowers the pressure with drops and tablets, then an eye specialist makes a small laser opening in the iris, and the other eye is often treated too. Narrow angles found at a routine check can be treated before an attack.
Your mother comes home from the market and lies down in a dark room. One eye is red and aching, the lights look blurred, and she has vomited twice. She says it is her migraine and she will sleep it off.
When a sudden red, painful eye comes with blurred vision and halos around lights, one cause cannot wait for morning: an attack of acute glaucoma, called glaukoma akut in Malay. This page explains what it is, why it is easy to miss, who is more at risk, where to go in Malaysia, and how a family can lower the risk of a first attack.
A sudden painful red eye with blurred vision and halos: is it an emergency?
Yes. The American Academy of Ophthalmology (AAO) calls an acute angle-closure glaucoma attack "a true eye emergency" and says to call your ophthalmologist right away or you might go blind. The NHS says to call 999 or go to A&E if glaucoma symptoms come on suddenly.
The reason is pressure. In this type of glaucoma the coloured part of the eye, the iris, blocks the drain where fluid leaves the eye, and the pressure inside climbs fast. A review in the Deutsches Ärzteblatt gives 50 to 80 mm Hg during an attack, against a normal 10 to 21.
In one study it cites, people who went on to have lasting glaucoma had waited about 56 hours before seeing a doctor, against about 20 hours for those who did not. That is one study, but it points the same way as the advice: hours matter.
The action: do not wait for the clinic to open or for the eye to settle. Go to a hospital emergency department the same day.
What are the signs of an acute glaucoma attack?
The AAO lists sudden blurred vision, severe eye pain, a headache, feeling sick, vomiting, and rainbow-coloured rings or halos around lights. The eye is usually red as well. The Deutsches Ärzteblatt review adds that the pupil may be a little wider than normal and may stop reacting to light, and that the pain can sit in the forehead on the same side.
Dim light can set off an attack, because the pupil widens. The AAO also describes milder early warnings in people at risk: blurred vision, halos, a mild headache or eye pain. Those deserve an eye check as soon as possible.
The NHS notes that uveitis (inflammation inside the eye) and an eye injury can cause similar symptoms. You cannot tell them apart at home, and all of them need a doctor. If the red eye is sticky and not painful, a red eye in a parent: pink eye, allergy or a problem that needs a doctor today sorts out the milder causes. The action: pain, blurred vision and halos together mean the emergency department.
Why is an acute glaucoma attack mistaken for a migraine or a stomach upset?
Because the headache, the nausea and the vomiting are the loudest symptoms, and the eye can seem a side issue. A review in Community Eye Health lists abdominal pain among the features and says it is sometimes misdiagnosed as gastroenteritis, a stomach infection. A drug review for non-eye doctors says headache, blurred vision, abdominal pain, nausea and vomiting are not specific to the eye.
The Deutsches Ärzteblatt review opens with a woman of 49 who had known migraine. She came to an emergency department with a strong headache, vomiting and blurred vision in one eye. Painkillers and anti-sickness medicine did not help, and a CT scan of the head showed nothing. An eye examination the next day found a pressure of 62 mm Hg. The review notes that almost a third of people with an attack first see a doctor who is not an eye doctor.
The useful clue is the eye: a red eye, halos around lights, and one eye seeing worse than the other. The action: if a headache or vomiting comes with any of those, say so at the emergency department door: "red painful eye, blurred, halos, possible acute glaucoma".
Who is more likely to have an acute glaucoma attack?
People who are older, women, people of Asian and Chinese ancestry, people who are long-sighted, and people with a family history. The drug review lists advanced age, female sex, strong family history, long-sightedness and Asian ethnicity. The Deutsches Ärzteblatt review says Asians are about three times as likely as Caucasians to have an acute attack and that the higher rate in Chinese people is not fully explained by eye measurements. The sources used here do not give a Malaysian figure.
The reason is the shape of the eye. A smaller, long-sighted eye (glasses that start with a plus sign) has a shallow front chamber and a narrow drain, and the lens thickens with age, which narrows the space further. Most people do not know their drain is narrow: the drug review says most attacks happen in people unaware that they are at risk.
Some medicines can tip a narrow eye into an attack. The sources name these classes: pupil-widening eye drops, decongestants and cold and flu medicines, cough mixtures, bronchodilators for asthma, antihistamines, antidepressants and anticonvulsants. The Deutsches Ärzteblatt review says such attacks are very rare. Do not stop a prescribed medicine on your own. Tell the doctor and pharmacist if you have ever been told you have narrow angles. The action: if your parent has these risk factors, ask the doctor about the angles at the next routine check.
What should we do, and where do we go in Malaysia?
Go to a hospital emergency department now, or call 999. The NHS adds that the person should not drive to hospital: ask someone to drive, or call an ambulance. Bring the medicines and the glasses. The Malaysian Ministry of Health and Academy of Medicine guideline on glaucoma lists acute angle closure for immediate referral.
Hospital Kuala Lumpur's emergency and trauma department states that it gives emergency medical care 24 hours a day. If you live elsewhere, look up your nearest hospital emergency department before you need it. The action: write down when it began, which eye, and every medicine taken, including cold tablets and eye drops, and take the list with you. For a child with a painful red eye the same rule applies, and the guide is this urgent? lists what cannot wait.
What happens at the hospital, and what comes after?
The doctor measures the eye pressure and gives treatment to bring it down. The Malaysian guideline describes medical treatment to break the attack and prepare for laser. The Deutsches Ärzteblatt review names eye drops that cut fluid production and acetazolamide, which can be given as a tablet or into a vein, and says pressure falls and symptoms usually ease. Community Eye Health adds painkillers and anti-sickness medicine.
Once the attack has settled, the next step is a small laser opening in the iris, called a laser peripheral iridotomy. It lets fluid pass around the block so the attack does not return. The review says surgery on the lens is also an option, especially over 50, and the eye specialist chooses case by case.
The other eye matters too. The review says about half of people with an attack in one eye have one in the other within five years. The Malaysian guideline says to schedule an iridotomy in the other eye if its angle is similar, and Community Eye Health says both eyes are treated when the other is at risk.
Afterwards the review reports that 15 percent of eyes in one study developed angle-closure glaucoma, and 21 percent in another had raised pressure, within about one to two years. The action: keep every follow-up visit, even if the eye feels normal, so the pressure and the optic nerve are checked.
Can narrow angles be treated before an attack, and who in the family should be checked?
Yes. Narrow angles can be found at a routine eye check and treated before they cause an attack. The drug review says people known to have narrow angles should see an eye doctor for gonioscopy, a look at the drain through a small mirror lens, to grade the risk. In a trial in China a preventive laser almost halved the risk of closure in people with suspicious angles, though in absolute terms few had an attack, so the choice is made person by person.
The risk factors above are the guide to who should be checked: a parent or sibling who has had an attack, long-sighted relatives, and adults of Chinese or other Asian ancestry. Glaucoma runs in families: who should be checked and from what age sets out who to bring in, and what the pressure test, the nerve scan and the field test show explains the visit. Sudden double vision is a separate emergency, covered in a parent suddenly sees double.
Dr Chan sees the whole family, so a parent or grandparent can be examined as well as the children. The action: if anyone in the family has had an attack, tell the adult relatives and ask for the drainage angle to be checked at the next eye visit.
- Severe eye pain or a headache, especially on the same side as the red eye.
- Blurred vision, or rainbow rings or halos around lights.
- Nausea or vomiting with any eye symptom.
- A pupil that looks bigger than the other and does not shrink in light.
Common questions
What is acute glaucoma?
What are the symptoms of an acute glaucoma attack?
Can an acute glaucoma attack be mistaken for a migraine or a stomach upset?
Should I go to hospital the same day for a painful red eye with halos?
Who is more at risk of acute glaucoma?
Can a medicine trigger an acute glaucoma attack?
What does the hospital do for an acute glaucoma attack?
Can narrow angles be found and treated before an attack?
- American Academy of Ophthalmology · Glaucoma symptoms · www.aao.org (opens in a new tab)
- NHS · Glaucoma · www.nhs.uk (opens in a new tab)
- Deutsches Ärzteblatt International 2021 · Acute closed-angle glaucoma, an ophthalmological emergency · pmc.ncbi.nlm.nih.gov (opens in a new tab)
- Community Eye Health 2018 · Emergency management: angle-closure glaucoma · pmc.ncbi.nlm.nih.gov (opens in a new tab)
- A review of drug-induced acute angle closure glaucoma for non-ophthalmologists · pmc.ncbi.nlm.nih.gov (opens in a new tab)
- Ministry of Health Malaysia and Academy of Medicine · Management of glaucoma, 2nd edition, quick reference · www.mso.org.my (opens in a new tab)
- Hospital Kuala Lumpur · Emergency and trauma department · hkl.moh.gov.my (opens in a new tab)