“My mother has glaucoma — does that mean I’ll get it too?” It’s one of the most common questions eye doctors hear, and for good reason. When a close family member is diagnosed with glaucoma, it’s natural to wonder whether you’re next.

The short answer: yes, glaucoma has a strong hereditary component. Having a first-degree relative (parent, sibling, or child) with glaucoma increases your risk by 4 to 9 times compared to the general population. But having the genetic predisposition doesn’t guarantee you’ll develop the disease — and knowing your risk gives you a powerful advantage.

This post explains exactly how genetics influence glaucoma, whether the type matters, what your family history means for you specifically, and the one thing you should do if glaucoma runs in your family.

Is Glaucoma Hereditary?

Yes. Glaucoma is one of the most heritable common eye conditions. Research consistently shows that genetics play a major role in determining who develops glaucoma:

• First-degree relatives of someone with glaucoma have a 4 to 9 times higher risk than the general population
• Siblings of glaucoma patients have the highest relative risk — approximately 10 times higher in some studies
• Twin studies show that identical twins are significantly more likely to both have glaucoma than fraternal twins
• Multiple genes have been identified that contribute to glaucoma susceptibility

However, glaucoma is not caused by a single gene with a simple inheritance pattern like some conditions. It’s what geneticists call a “complex trait” — meaning multiple genes, combined with environmental factors and age-related changes, determine whether someone ultimately develops the disease.

Think of it this way: your genes set the stage (your eye anatomy, how your drainage system is built, how your optic nerve responds to pressure), but other factors determine whether the disease actually develops.

Is Narrow Angle Glaucoma Specifically Hereditary?

Narrow angle glaucoma has a particularly strong hereditary component because it’s driven largely by the physical anatomy of the eye — and eye anatomy is heavily determined by genetics.

The structural features that create narrow angles tend to run in families:

• Shorter axial length — smaller eyes with less space inside
• Shallow anterior chamber — the front portion of the eye is shallower than average
• Thicker lens — the natural lens takes up more space, pushing the iris forward
• Specific iris configurations — such as plateau iris, where the iris root is positioned differently

If your parent or sibling has been diagnosed with narrow angles or narrow angle glaucoma, there’s a meaningful chance that you share similar eye anatomy. This doesn’t mean you’ll definitely develop glaucoma, but it does mean you should be screened.

Certain ethnic backgrounds carry higher structural risk for narrow angles due to genetic differences in eye anatomy. People of East Asian, Southeast Asian, and Inuit descent have significantly higher rates of angle closure glaucoma compared to European populations.

Does It Matter Which Parent Has Glaucoma?

This is a question that comes up frequently — and the research provides a reassuring answer: the risk is similar regardless of which side of the family has glaucoma.

From Your Father

Glaucoma risk from your father’s side is just as significant as from your mother’s side. The genes associated with glaucoma susceptibility are located on regular chromosomes (autosomes), not sex chromosomes. If your father has glaucoma, you inherited half of his genetic material, including any glaucoma-related gene variants.

From Your Mother

The same applies to maternal inheritance. Your mother’s glaucoma diagnosis carries equal weight as a risk factor. Some studies have suggested a very slight maternal bias in certain populations, but the difference is small enough that clinical guidelines treat maternal and paternal history equivalently.

From Grandparents

Grandparent history still matters, though the risk is somewhat lower than having an affected parent. You share approximately 25% of your DNA with each grandparent, so glaucoma susceptibility genes can certainly be passed down across generations. If a grandparent had glaucoma — especially if they lost significant vision from it — mention this to your eye doctor.

The Bottom Line

Don’t try to calculate your exact risk based on which relative is affected. Any family history of glaucoma — mother, father, sibling, grandparent — is a meaningful risk factor that warrants proactive screening.

What Should You Do If Glaucoma Runs in Your Family?

If you have a family member with glaucoma, there are concrete steps you can take to protect your vision. Early detection is the single most important factor in glaucoma outcomes, and knowing your family history gives you the opportunity to catch it before damage begins.

1. Start Comprehensive Eye Exams Earlier

The general population is advised to get baseline glaucoma screening at age 40. If you have a family history, start earlier:

• First-degree relative affected: Begin comprehensive eye exams at age 35 or earlier
• Multiple affected relatives: Begin at age 30 or as soon as possible
• Already over 40 with family history: Get screened now if you haven’t recently

2. Tell Your Eye Doctor — Specifically

When you see your eye doctor, don’t just say “my mom has eye problems.” Be specific:

• Who has glaucoma (parent, sibling, grandparent)
• What type, if known (open angle vs. narrow angle/angle closure)
• How severe it is or was (vision loss, surgery, blindness)
• What age they were diagnosed

This information helps your doctor determine the appropriate screening frequency and what specific tests to prioritize.

3. Get the Right Tests

A standard eye exam (checking vision and looking at the back of the eye) is not sufficient for glaucoma screening. Make sure your exam includes:

• Intraocular pressure measurement (tonometry)
• Gonioscopy — to assess your drainage angles
• Optic nerve imaging (OCT)
• Visual field testing — if any other tests raise concern

4. Maintain Your Screening Schedule

Glaucoma develops gradually. A normal result today doesn’t mean you’re permanently in the clear. Stick to your recommended screening schedule:

• Every 1-2 years if you have a family history and normal results
• More frequently if your doctor identifies risk factors like elevated pressure, suspicious optic nerve appearance, or narrow angles

5. Know the Symptoms of Narrow Angle Glaucoma

If your family member has narrow angle glaucoma specifically, be aware of the acute attack symptoms that require emergency care: sudden severe eye pain, blurred vision, halos around lights, nausea, and headache. Knowing these symptoms could save your sight.

Is There Genetic Testing for Glaucoma?

Genetic testing for glaucoma is an active area of research, but it’s not yet part of routine clinical care. Here’s the current state:

What’s Been Discovered

• Over 100 genetic loci have been associated with glaucoma risk
• Key genes include MYOC, OPTN, WDR36, and TBK1 for open angle glaucoma
• For angle closure, genes affecting eye development and anterior segment anatomy are being studied
• Polygenic risk scores (combining many gene variants) are being developed

Why It’s Not Standard Practice Yet

• No single gene test can reliably predict who will or won’t develop glaucoma
• The genetics are complex — many genes each contribute a small amount of risk
• Clinical screening (eye exams) remains more practical and accurate for most people
• Insurance typically doesn’t cover genetic testing for glaucoma

When Genetic Testing Might Be Useful

• Early-onset glaucoma in young adults (under 35) — may indicate a strong single-gene cause
• Research studies investigating glaucoma genetics
• Potentially in the future as polygenic risk scores become more validated

For now, the most effective screening remains a comprehensive eye exam with a doctor who knows your family history. Genetic testing is something to watch in the coming years, but it doesn’t replace the need for regular clinical exams today.

Frequently Asked Questions

If my parent has glaucoma, what are my chances of getting it?

Having one parent with glaucoma increases your risk by approximately 4 to 9 times compared to someone with no family history. However, this doesn’t translate to a 50% or higher chance of developing it — the absolute risk depends on many factors including your age, ethnicity, eye anatomy, and overall health. Regular screening is the appropriate response, not alarm.

Can glaucoma skip a generation?

Yes. Because glaucoma involves multiple genes and environmental factors, it’s entirely possible for a grandparent to have glaucoma, the parent to be unaffected, and the grandchild to develop it. This is why grandparent history is still a relevant risk factor to report to your eye doctor.

At what age should I start screening if glaucoma runs in my family?

With a first-degree relative (parent or sibling) affected, begin comprehensive eye exams including intraocular pressure measurement and optic nerve evaluation by age 35. If multiple family members are affected, or if the family member developed glaucoma at a young age, start even earlier. After age 40, annual or biennial exams are recommended regardless of family history.

Is angle closure (narrow angle) glaucoma more hereditary than open angle?

The anatomical component of narrow angle glaucoma — the shallow anterior chamber and narrow angle structure — is highly heritable because it’s determined by eye anatomy. However, open angle glaucoma also has a strong genetic basis. Both types show significant familial clustering. The difference is that narrow angle risk is somewhat easier to detect early through measurement of the anterior chamber and angle.

My sibling was just diagnosed with glaucoma. What should I do?

Sibling diagnosis is one of the strongest family risk indicators. Schedule a comprehensive eye exam as soon as possible — specifically one that includes gonioscopy (angle assessment), intraocular pressure measurement, and optic nerve imaging. Tell your eye doctor about your sibling’s diagnosis, including the type and their age at diagnosis. Establish a regular screening schedule based on your doctor’s assessment of your individual risk.

Your Family History Is Your Advantage

Knowing that glaucoma runs in your family isn’t a reason to worry — it’s a reason to act. Patients who are screened early because of family history are among the most likely to catch glaucoma in its earliest, most treatable stages.

At Garibaldi Eye Care, we take family history seriously. Our comprehensive glaucoma evaluations include gonioscopy, optic nerve imaging, and pressure assessment — everything needed to determine whether you’ve inherited a predisposition and whether any early changes have begun. If narrow angles run in your family, we can assess your anatomy and discuss whether preventive laser iridotomy is appropriate.

Don’t wait for symptoms. By the time glaucoma causes noticeable vision changes, significant damage has already occurred. Early detection is the best protection. Contact us today to schedule your comprehensive eye exam.

If glaucoma runs in your family, don’t wait — your eye doctor in Squamish can screen you early.