Glaucoma runs in families: who in the family should be checked, and from what age
Glaucoma gives no early warning, and a parent, brother or sister with it raises your own risk. Here is who in the family should be checked, what the check involves, and what to watch for in a baby.
- Having a parent, brother or sister with glaucoma raises your own risk. Studies disagree on the size: the Baltimore Eye Survey found odds 3.69 times higher with an affected sibling and 2.17 times with a parent, and the small Rotterdam Study found a risk ratio of 9.2 with a very wide margin of error.
- Open-angle glaucoma has no early symptoms, and the damage cannot be reversed, so the check has to come before the symptoms do.
- A proper check is more than a pressure reading: it looks at the optic nerve, tests side vision and inspects the drainage angle.
- No guideline sets one starting age. Relatives in screening studies were invited from 40, and my own advice is a full check in your 40s, sooner if your relative was diagnosed young.
- Adult-type glaucoma does not call for a pressure test in a healthy young child, but the family history should be told at every child's eye check. In babies the signs are different and visible: tearing, light sensitivity and a large or cloudy cornea.
If your father, mother, brother or sister has glaucoma, your own risk of it is higher, and the only way to find out early is a full eye check, because glaucoma does not hurt and does not blur your sight until it is well advanced. My advice is a check in your 40s, earlier if your relative was diagnosed young, and the same family history should be mentioned at every child's eye check too.
This page is for the family that has just heard the word "glaucoma" about Ah Gong or Ah Ma, an uncle or a sibling. It says how much the risk goes up, who should go, what the check involves, what the condition looks like in a baby, and what Malaysian studies show.
Does glaucoma really run in families?
Yes. Glaucoma is damage to the main nerve that joins the eye to the brain, and the NHS and the American Academy of Ophthalmology both list a parent, brother or sister with glaucoma as a risk factor. How large the risk is depends on the study and on which relative you ask about.
The Baltimore Eye Survey looked at 5,308 people aged 40 and over, 161 of whom had the commonest type, primary open-angle glaucoma. After adjusting for age, the odds of having it were 3.69 times higher in people with an affected sibling and 2.17 times higher with an affected parent.
The Rotterdam Study examined 48 relatives of patients and 155 relatives of people without glaucoma. Glaucoma was found in 10.4 percent of the patients' siblings and 1.1 percent of their grown-up children. Over a lifetime, the risk worked out at 22.0 percent against 2.3 percent, a risk ratio of 9.2. The confidence interval ran from 1.2 to 73.9, which is the statistician's way of saying that this was a small study and the figure is rough.
So I give you a range and not one number: several times higher, varying by study and by relative. A higher risk is not a diagnosis. Even in the Rotterdam figures, most relatives did not develop glaucoma. The point of a check is to find the ones who will, early enough to act.
Which relatives should be checked, and from what age?
Parents, brothers, sisters and grown-up children of someone with glaucoma. No guideline fixes one starting age for everyone, so I will tell you what exists and then give you my own advice, marked as opinion.
The American Academy of Ophthalmology says people with a family history of eye disease should ask their ophthalmologist how often to be examined. A Thai screening study of first-degree relatives invited those aged 40 and over, and found glaucoma in 8.3 percent of the relatives who came, with another 19.2 percent labelled glaucoma suspects, meaning something looked unusual and needed watching. The NHS lists being over 50 as a risk in its own right.
My advice: book a full check in your 40s, and sooner if your relative was diagnosed young. Juvenile glaucoma, which starts in childhood or youth, is a recognised form, and the Malaysian study below found it in relatives. If you are not sure when your relative was diagnosed, ask them. It is the most useful sentence you can take to your own appointment.
Why is glaucoma called silent, and can I wait for symptoms?
No, you cannot wait for symptoms, because there usually are none. The American Academy of Ophthalmology says open-angle glaucoma has no warning signs or obvious symptoms in the early stages, and most people notice no change in their vision until the damage is quite severe. That is why it is called the silent thief of sight.
The NHS adds the part that makes early checking worth the trouble: the damage cannot be reversed. Treatment, which can be eye drops, laser or surgery, aims to stop vision getting worse, not to bring back what has gone. Finding glaucoma while the nerve is still mostly healthy is the whole game.
There is one different, sudden form. Intense eye pain, a red eye and rainbow-coloured circles around bright lights are the NHS's signs of a sudden glaucoma attack, and they need emergency care, not a booking next week.
What happens at a glaucoma check?
Several tests, because no single one is enough. The Academy lists them: eye pressure, a look at the optic nerve (the cable at the back of the eye), a visual field test of your side vision, a look at the drainage angle inside the eye, a measurement of corneal thickness, and often a scan or photograph of the nerve. It says plainly that a screening that only checks eye pressure is not enough.
That matches what the Rotterdam researchers found in families. The earliest and clearest sign was not high pressure but an enlarged cup in the optic nerve, the hollow in the centre of the nerve's surface that grows as nerve fibres are lost. A pressure reading can look normal while the nerve is already changing.
Some of the tests use eye drops, and the National Eye Institute describes drops that widen the pupil as part of a full examination. Ask the clinic beforehand whether your pupils will be widened that day, and if so, do not plan to drive yourself home.
Do the children and grandchildren need checking too?
Not for adult-type glaucoma, which is a condition of later life, so a healthy five-year-old does not need a pressure test because Ah Gong has glaucoma. But the history still matters. The American Academy of Ophthalmology lists a family history of glaucoma, along with squint, lazy eye, retinoblastoma and childhood cataract, among the things that put a child at higher risk of eye problems. Say it at the first visit, and at every check after, rather than waiting to be asked.
Three more things belong in the same conversation. Steroid medicine, in eye drops, tablets or inhalers, can raise eye pressure, and eye checks for children on long-term steroid medication explains who needs watching. The same goes for steroid drops bought from a pharmacy for a red eye, which my colleague Dr Catherine Chow covers in eye drops from the pharmacy: redness relief and steroid drops. And the NHS lists short-sightedness as a glaucoma risk, one of the reasons a strong prescription is a health matter as well as a matter of comfort, as high myopia: what changes once the number gets high explains.
If the diabetes runs in the family as well, the same visit can cover it. The NHS lists diabetes as a glaucoma risk too, and eye checks in a family with diabetes lays out the schedule.
What does glaucoma look like in a baby?
Quite different from the adult kind, and visible. The paediatric eye body AAPOS lists too much tearing, eye pain in bright light, and a large or cloudy cornea, the clear window at the front. In a baby the wall of the eye is still soft, so raised pressure can enlarge the eye itself.
The American Academy of Ophthalmology says about eight in ten cases are diagnosed in the first year of life, and that in childhood glaucoma can be aggressive. Most watering in babies is a blocked tear duct, so watering alone is not a reason to panic. A baby who waters, hates daylight and has an eye that looks bigger or hazier is a reason to be seen this week. Big beautiful eyes can be a warning sign sets out how to tell the two apart.
What do Malaysian studies show about glaucoma and families?
That relatives are not being reached. In the National Eye Survey II, which examined 15,000 Malaysians aged 50 and over, glaucoma caused 6.6 percent of blindness, behind untreated cataract at 58.6 percent and diabetic retinopathy at 10.4 percent. The survey judged 86.3 percent of the causes of blindness avoidable.
A study at Hospital Universiti Sains Malaysia in Kelantan began with 70 patients with glaucoma and identified 368 first-degree relatives. Only 45 came for screening. Of those, five, about one in nine, were found to have juvenile open-angle glaucoma. The authors put the low attendance down to relatives living and working outside Kelantan, and to a lack of awareness of glaucoma. A small community survey elsewhere in Malaysia found that only about one in four respondents was aware of it.
The Ministry of Health also publishes a clinical practice guideline on the management of glaucoma, now in its second edition (2017). Its advice on screening relatives is not quoted here.
What can our family do this week?
Four small things. Ask your relative which type of glaucoma it is and how old they were when it was found, and write the answers down. Tell your brothers and sisters, wherever they live. Book your own full check, with pressure, nerve and side vision, and take the answers with you; eye checks for the whole family says what to watch for at every age. And tell your children's eye doctor about the family history at their next visit. A family history is information, not a sentence, and it is the one risk factor you can turn into an appointment.
- There is intense eye pain with a red eye, or rainbow-coloured circles around bright lights.
- A baby's eye looks larger or hazier than before, waters constantly and the baby cannot bear daylight.
- Vision in one or both eyes drops suddenly.
Common questions
Is glaucoma hereditary?
My mother has glaucoma. At what age should I get my eyes checked?
My father has glaucoma. Does my child need a glaucoma test?
Does glaucoma give any warning signs?
Can glaucoma be cured or the damage reversed?
What are the signs of glaucoma in a baby?
- Archives of Ophthalmology 1994 · Family history and risk of primary open angle glaucoma: the Baltimore Eye Survey · pubmed.ncbi.nlm.nih.gov
- Archives of Ophthalmology 1998 · Genetic risk of primary open-angle glaucoma: population-based familial aggregation study (Rotterdam Study) · pubmed.ncbi.nlm.nih.gov
- American Academy of Ophthalmology · Glaucoma symptoms · www.aao.org
- American Academy of Ophthalmology · Glaucoma diagnosis · www.aao.org
- NHS · Glaucoma · www.nhs.uk
- NHS · Glaucoma, causes · www.nhs.uk
- National Eye Institute · Glaucoma · www.nei.nih.gov
- Clinical Ophthalmology 2024 · Glaucoma screening uptake among first-degree relatives, community-based and hospital-based approaches · pubmed.ncbi.nlm.nih.gov
- Cureus 2022 · Opportunistic eye screening among first-degree relatives of glaucoma patients at a suburban tertiary center in Malaysia · pubmed.ncbi.nlm.nih.gov
- PLoS One 2018 · Estimates of visual impairment and its causes from the National Eye Survey in Malaysia (NESII) · pubmed.ncbi.nlm.nih.gov
- American Academy of Ophthalmology · Eye screening for children · www.aao.org
- AAPOS · Glaucoma in children · aapos.org
- American Academy of Ophthalmology · Childhood glaucoma · www.aao.org
- Ministry of Health Malaysia · Clinical practice guidelines: management of glaucoma, 2nd edition (2017), catalogue record · localcontent.library.uitm.edu.my