Understanding Glaucoma: Symptoms, Causes, and Prevention

Glaucoma is one of the leading causes of vision loss, yet many people do not realize they have it until damage has already occurred. The condition often develops slowly and without noticeable symptoms, so early detection and treatment greatly reduce the risk of serious damage.

What Is Glaucoma?

Glaucoma is a group of eye diseases that damage the optic nerve (the structure that carries visual information from the eye to the brain). This damage happens when pressure inside the eye becomes too high. Over time, pressure can damage the optic nerve and cause gradual vision loss.

The vision loss caused by glaucoma is permanent, but early detection and proper glaucoma treatment can slow or prevent further damage. However, because glaucoma can progress quietly, regular glaucoma testing during an eye examination is important.

What Causes Glaucoma?

Glaucoma causes usually relate to problems with how fluid moves through the eye.

Inside the eye, a clear fluid called aqueous humor circulates to nourish tissues and maintain healthy pressure. Normally, this fluid drains through a small drainage angle located where the iris and cornea meet. When this system does not work efficiently, fluid builds up and eye pressure increases.

However, eye pressure is not the only factor involved. Some people develop glaucoma even when their eye pressure is within a normal range. In these cases, the optic nerve may be more sensitive to pressure or reduced blood flow.

Who Is at Risk for Glaucoma?

Anyone can develop glaucoma, but certain risk factors make the condition more likely.

One of the most common risk factors is age. The risk of glaucoma increases after age 40 and rises further after age 60. As the eye ages, changes in fluid drainage and optic nerve health can increase vulnerability to damage.

A family history of glaucoma is another important factor. If a parent or sibling has glaucoma, your risk may be significantly higher. Genetic factors can influence how the eye regulates pressure and how sensitive the optic nerve may be to damage.

Certain health conditions may also raise the risk of glaucoma. These include:

• Diabetes
• High blood pressure
• Sleep Apnea
• Poor circulation affecting the optic nerve

Eye structure can also play a role. For example, people with thin corneas may be at higher risk because this masks the true pressure inside the eye and may appear normal when it is actually elevated.

Some medications may contribute to glaucoma as well. Long-term use of steroid medications, including steroid eye drops, can increase eye pressure in some individuals. Eye injuries, inflammation inside the eye, and other eye diseases may also increase glaucoma risk.

Because glaucoma often develops without early symptoms, people with one or more glaucoma risk factors should schedule a regular eye examination. Early monitoring allows eye specialists to detect changes in eye pressure and optic nerve health before permanent vision loss occurs.

Types of Glaucoma

Glaucoma is not a single disease. It includes several conditions that damage the optic nerve in different ways. The most common types differ in how eye pressure builds and how quickly symptoms develop.

Open-Angle Glaucoma

Open-angle glaucoma is the most common form of glaucoma. It develops slowly over time and often does not cause noticeable symptoms in the early stages.

In this condition, the drainage angle inside the eye remains open, but fluid does not flow out efficiently. This causes a gradual increase in eye pressure, which can slowly damage the optic nerve. Vision loss typically begins in the outer (peripheral) vision and may go unnoticed until the disease progresses.

Because symptoms often appear late, regular eye examinations and glaucoma testing are important for early detection.

Angle-Closure Glaucoma

Angle-closure glaucoma (sometimes called acute angle closure glaucoma) occurs when the drainage angle becomes blocked. This prevents fluid from leaving the eye, leading to a rapid increase in eye pressure, decreased circulation within the eye and damage to the optic nerve.

Unlike open-angle glaucoma, this type may appear suddenly and is considered a medical emergency. Symptoms may include:

• Severe eye pain
• Blurred vision
• Headache
• Nausea or vomiting
• Halos around lights

Immediate medical care is needed to reduce pressure and protect the optic nerve.

Secondary Glaucoma

Secondary glaucoma develops due to another eye condition or a medical factor that interferes with fluid drainage.

Common causes of secondary glaucoma may include:

• Eye injuries
• Inflammation inside the eye
• Long-term use of steroid medications
• Certain eye diseases or medical conditions

Treatment focuses on both lowering eye pressure and addressing the condition that triggered the glaucoma.

What Are the Symptoms of Glaucoma?

Most people with open-angle glaucoma (the most common form of the disease) do not notice early symptoms.

Vision may appear normal for years while damage to the optic nerve slowly develops. That is why glaucoma is often detected during an eye exam rather than through obvious warning signs.

As glaucoma progresses, the first noticeable change is often a gradual loss of peripheral vision. This means side vision begins to narrow. Many people do not recognize the change at first because the brain adapts and fills in missing visual information.

In advanced stages, this can lead to tunnel vision (where a person can only see what is directly in front of them). Once vision loss from glaucoma occurs, it cannot be reversed.

Some forms of glaucoma develop very differently. Acute angle-closure glaucoma can appear suddenly and cause severe symptoms that require immediate medical care (see the section above for more details).

How Is Glaucoma Diagnosed?

In most cases, only a comprehensive eye exam can detect glaucoma early since many people do not notice its early symptoms.

During an eye examination for glaucoma, your eye doctor performs several tests to evaluate eye pressure, optic nerve health, and visual function. Common forms of glaucoma testing include:

• Tonometry – This test measures the pressure inside the eye.
• Optic nerve evaluation – Your doctor examines the optic nerve at the back of the eye using specialized instruments.
• Visual field testing – This test checks your peripheral, or side, vision.
• Imaging of the optic nerve and retinal layers – Advanced imaging technology produces detailed images of the optic nerve and surrounding tissues. These images allow doctors to measure nerve fiber thickness and monitor small changes over time.

These tests work together to give a complete picture of eye health. In many cases, glaucoma is diagnosed by identifying patterns across multiple tests rather than relying on a single measurement.

Glaucoma Treatment

The goal of glaucoma treatment is to lower eye pressure and protect the optic nerve from further damage. While vision already lost to glaucoma cannot be restored, treatment can slow or stop the progression of the disease when it is detected early.

The right treatment plan depends on careful diagnosis and ongoing monitoring. Common glaucoma treatments include:

• Eye drops for glaucoma
• Laser therapy
• Glaucoma surgery

For a deeper look, read Glaucoma Treatment Options: What to Expect from Drops, Lasers, and Surgery.

Can Glaucoma Be Prevented?

You cannot eliminate your risk of glaucoma, but you can lower it to some degree. Steps that help prevent glaucoma include:

• Getting a yearly eye exam
• Controlling high blood pressure
• Staying physically active
• Protecting your eyes from injury
• Working carefully with your doctor to manage diabetes
• Treat sleep apnea

Regular eye exams are by far the most effective way to prevent vision damage from glaucoma. For people at high risk, your eye doctor may recommend visits every six months.

Protecting Your Vision Through Early Detection

While glaucoma cannot always be prevented, early diagnosis and proper treatment can slow or stop the progression of the disease.

If you are over age 40, have a family history of glaucoma, or have not had a recent eye exam, it is time to schedule an evaluation.

Schedule a consultation with our Heart of Texas Eye Care team, serving Dripping Springs, Austin, Kyle, Bee Cave, Marble Falls, and other surrounding areas. Contact us at (512) 213-2220 today!

*Individual results may vary