Understanding what causes glaucoma starts with the optic nerve, which carries visual information from your eye to your brain. Glaucoma damages this nerve, often in connection with increased eye pressure. However, pressure alone does not explain every case, and the causes of common forms remain incompletely understood.
A family member’s diagnosis or an elevated pressure reading may leave you wondering about your own risk. Neither means you will definitely develop glaucoma. Knowing your risk factors helps you and your eye doctor decide what monitoring you need.
If glaucoma runs in your family or you have concerns about your eye pressure, schedule an eye exam at Barnet Dulaney Perkins Eye Center.
How Eye Pressure Can Affect the Optic Nerve
Your eye constantly produces a clear fluid called aqueous humor. This fluid circulates through the front of your eye and drains through tissue near the junction of the iris and cornea.
When fluid drains too slowly, pressure inside the eye can rise. Higher pressure can damage the optic nerve over time, leading to permanent vision loss.
However, people differ in how much pressure their optic nerves can tolerate. Some have elevated pressure without detectable glaucoma damage, a condition called ocular hypertension. Others develop glaucoma despite pressure readings within the usual range.
That is why a pressure check alone cannot establish or rule out glaucoma. Your doctor also evaluates the optic nerve and your vision.
How Glaucoma Develops in Different Forms
Open-Angle Glaucoma
In open-angle glaucoma, the drainage angle remains open, but fluid may pass through the drainage tissue too slowly. Pressure can build gradually. This common form often develops without noticeable early symptoms.
Normal-Tension Glaucoma
Normal-tension glaucoma is a form of open-angle glaucoma that develops without unusually high pressure readings. Researchers are still investigating its causes. Differences in optic nerve sensitivity and blood supply may contribute.
A normal pressure reading therefore does not replace a complete assessment of your eye health.
Angle-Closure Glaucoma
Angle closure happens when the iris blocks the eye’s drainage angle. It may develop gradually or occur suddenly, causing a rapid increase in pressure.
Sudden severe eye pain, redness, blurred vision, or halos around lights, especially with nausea or vomiting, require immediate assessment. Contact an eye doctor immediately or seek emergency care. Do not wait for a routine appointment.
Secondary Glaucoma
Some forms develop because of another condition or exposure, such as an eye injury, inflammation, or steroid medication. Identifying that underlying factor helps your doctor guide treatment.
Glaucoma Risk Factors to Discuss With Your Doctor
Risk factors make glaucoma more likely, but they do not predict with certainty who will develop it. Your doctor considers your history and examination findings together.
• Increasing age, particularly after age 60.
• A parent, sibling, or other family member with glaucoma.
• Elevated eye pressure.
• Certain eye characteristics, such as significant nearsightedness or a thin central cornea.
• A history of eye injury or inflammation.
• Long-term steroid medication use.
• Health conditions such as diabetes.
Risk also varies across populations and glaucoma types. Black adults face increased risk at younger ages, and Hispanic/Latino adults face increased risk as they age. Your personal history still matters, regardless of your background.
Family History Matters
Glaucoma can run in families. If a close relative has it, tell your eye doctor even if you see clearly. If possible, ask which type they have and when they received their diagnosis.
Share Your Medication History
Steroid medicines can raise eye pressure in some people. Bring a medication list, including eye drops, inhalers, creams, and pills. Do not stop prescribed medication on your own. Your eye doctor and prescribing clinician can advise you about monitoring or changes.
Protecting Your Vision Starts With Knowing Your Risk
You cannot change your age or family history, but you can act on that information. A comprehensive eye exam helps your doctor assess your risk and look for changes before you notice symptoms.
Before your appointment, gather your family eye history, medication list, and information about previous eye injuries. Bring any earlier eye test records you have.
Ask your doctor:
• Which risk factors apply to me?
• Does my optic nerve show any concerning changes?
• Do I need additional testing or monitoring?
• When should I return?
Your examination schedule depends on your findings and risk. If testing is recommended, our guide to understanding glaucoma test results explains how the different tests fit together.
Why Treatment Focuses on Eye Pressure
Although the causes of glaucoma vary, lowering eye pressure can help slow further damage, including in normal-tension glaucoma. Treatment may involve medicines, laser procedures, or surgery. The appropriate approach depends on your glaucoma type and individual findings.
Treatment cannot restore vision already lost to glaucoma. Learn more about glaucoma treatment options and discuss your choices with your eye doctor.
Understand Your Personal Glaucoma Risk
Knowing what causes glaucoma can help you ask better questions, but an examination is necessary to assess your own eyes. Barnet Dulaney Perkins Eye Center provides glaucoma evaluation and care in Arizona.
If you have a family history of glaucoma, an elevated pressure reading, or concerns about your risk, book your eye exam to discuss your next steps.