Part 2 | Different Types of Glaucoma: What Patients Should Know

Glaucoma is a group of eye diseases that can damage the optic nerve, the nerve that carries visual information from the eye to the brain. If glaucoma is not detected and treated early, it can lead to permanent vision loss.

Many people think glaucoma is only caused by “high eye pressure,” but that is not always the case. Some people have high eye pressure without glaucoma, while others can develop glaucoma even when their eye pressure is considered normal.

Because glaucoma often has no early symptoms, a comprehensive eye exam is one of the best ways to detect changes before vision loss becomes noticeable.

A doctor examines a patient's eye with imaging equipment in a clinic. Posters about glaucoma and eye health are visible in the background.

1. Primary Open-Angle Glaucoma

Primary open-angle glaucoma is the most common type of glaucoma in the United States. In this form, the eye’s drainage angle remains open, but fluid does not drain as well as it should. Over time, this can increase eye pressure and damage the optic nerve.

Open-angle glaucoma usually develops slowly. Many patients do not feel pain, redness, or sudden vision changes in the early stages. Peripheral vision is often affected first, which means a person may not notice a problem until the disease is more advanced.

This is why routine testing is so important. Eye doctors monitor the optic nerve, eye pressure, visual field, and retinal nerve fiber layer to look for early signs of glaucoma damage.

Infographic titled Open-Angle Glaucoma from OPT-ISM Eye Care Blog, showing an eye doctor explaining symptoms and testing.

2. Angle-Closure Glaucoma

Angle-closure glaucoma, also called narrow-angle glaucoma or closed-angle glaucoma, occurs when the drainage angle between the iris and cornea becomes blocked. This can cause eye pressure to rise quickly or gradually, depending on the type.

An acute angle-closure attack is a medical emergency. Symptoms may include:

• Severe eye pain

• Red eye

• Blurry vision

• Halos around lights

• Headache

• Nausea or vomiting

Patients with narrow angles may not know they are at risk unless an eye doctor evaluates the drainage angle. This is one reason a comprehensive eye exam may include a test called gonioscopy, which allows the doctor to view the angle structure inside the eye

OPT-ISM Eye Care Blog infographic on angle-closure glaucoma, listing symptoms and showing an eye doctor explaining eye pressure.

3. Normal-Tension Glaucoma

Normal-tension glaucoma is a type of glaucoma where optic nerve damage occurs even though eye pressure is not above the normal range.

This can be confusing for patients because they may assume their eyes are healthy if their pressure is “normal.” However, some optic nerves are more sensitive to pressure, blood flow changes, or other risk factors.

For this reason, glaucoma evaluation is not based on eye pressure alone. The optic nerve appearance, visual field testing, OCT imaging, corneal thickness, family history, and other risk factors all help determine whether glaucoma is present or progressing.

OPT-ISM Eye Care Blog poster on Normal-Tension Glaucoma; doctor talks to patient in clinic with eye chart and optic nerve graphics.

4. Secondary Glaucoma

Secondary glaucoma happens when another eye condition, medical problem, medication, injury, or surgery contributes to increased eye pressure or optic nerve damage.

Examples of secondary glaucoma may include:

• Glaucoma related to eye trauma

• Steroid-induced glaucoma

• Pigmentary glaucoma

• Pseudoexfoliative glaucoma

• Inflammatory glaucoma

• Neovascular glaucoma

• Glaucoma after certain eye surgeries

Because secondary glaucoma has an identifiable cause, treatment may involve managing both the eye pressure and the underlying condition contributing to the pressure change.

Infographic titled Secondary Glaucoma shows a doctor explaining to a patient in an eye clinic, with eye chart, exam tools, and tips.

5. Congenital or Childhood Glaucoma

Congenital glaucoma is a rare type of glaucoma that occurs in babies or young children. It may happen when the eye’s drainage system does not develop properly.

Signs in children can include:

• Cloudy-looking cornea

• Light sensitivity

• Excessive tearing

• Enlarged-looking eyes

• Frequent eye rubbing

Children with these symptoms should be evaluated promptly by an eye care professional.

Eye care blog poster on congenital glaucoma, with doctor advising a mother and child in a clinic beside an eye chart and exam icons.

How Eye Doctors Check for Glaucoma

A glaucoma evaluation may include several tests, because no single test tells the whole story. Common glaucoma testing may include:

Eye pressure measurement

This checks the pressure inside the eye, also called intraocular pressure.

Optic nerve evaluation

The doctor examines the optic nerve for signs of thinning, cupping, asymmetry, or damage.

OCT imaging

OCT imaging measures the retinal nerve fiber layer and optic nerve structure. This helps detect subtle changes over time.

Visual field testing

A visual field test checks for blind spots or side vision loss that may occur with glaucoma.

Corneal thickness measurement

Corneal thickness can affect eye pressure readings and may help with glaucoma risk assessment.

Gonioscopy

This test allows the doctor to examine the drainage angle and determine whether the angle is open, narrow, or closed.

Infographic about how eye doctors check for glaucoma, with doctor and patient, eye test icons, eye chart, OCT images, and myoptism.com

Why Early Detection Matters

Glaucoma vision loss is usually permanent, but early detection and treatment can help slow or prevent further damage. Treatment may include prescription eye drops, laser procedures, surgery, or referral to a glaucoma specialist depending on the type and severity.

The most important step is regular monitoring. Glaucoma is often a long-term condition, and small changes over time can be meaningful.

Schedule a Glaucoma Evaluation in Tampa

At OPT-ISM, we provide comprehensive eye exams and glaucoma testing to help evaluate eye pressure, optic nerve health, and vision changes. If you have a family history of glaucoma, have been told your eye pressure is high, or are experiencing changes in vision, an eye exam can help determine your risk and whether additional monitoring is needed.

Protecting your vision starts with early detection. Schedule an eye exam with OPT-ISM today.