Understanding Glaucoma: Causes, Symptoms, and Treatment

University Ophthalmology Associates provides expert glaucoma diagnosis and treatment in Chicago. Our board-certified doctors serve Chicago, Skokie, Libertyville, and Oak Brook, IL.

Glaucoma is a vision-threatening disease that can cause optic nerve damage. This most often occurs from high pressure caused by poor drainage of a fluid formed in the eye, aqueous humor, which supplies nutrients to the cornea and lens. Glaucoma is one of the leading causes of vision loss. Because it involves progressive and irreversible damage to the optic nerve, it is important to catch this disease early.

Two Types of Glaucoma

There are two basic types of glaucoma. They include:

Open-angle glaucoma is the most common type that occurs in approximately 90 percent of those who suffer from the disease. This condition can develop gradually and be undetected for years. It can slowly cause vision loss. Treatment typically includes medications (drops), and sometimes surgery is indicated.

Closed-angle glaucoma (also called angle-closure glaucoma) is much more rapid in the onset. This type affects less than ten percent of glaucoma patients. Symptoms occur suddenly and are much more severe, but vision can be preserved with prompt, effective treatment. Treatment often includes a laser.

Symptoms of Glaucoma

Open-angle glaucoma signs and symptoms include:

• Gradual loss of peripheral vision, usually in both eyes
• Tunnel vision in the advanced stages

Closed-angle glaucoma signs and symptoms include:

• Severe eye pain

• Nausea and vomiting, along with severe eye pain
• Sudden onset of visual disturbance, often in low light
• Blurred vision
• Halos around lights
• Reddening of the eye

What Causes Glaucoma?

In open-angle glaucoma, the drainage channels in the angle (called the trabecular meshwork) are partially blocked, causing the aqueous humor to drain out of the eye too slowly. The exact cause of open-angle glaucoma remains unknown.

Closed-angle glaucoma occurs when the iris protrudes forward to narrow or block the drainage angle formed by the cornea and the iris. As a result, aqueous fluid can no longer reach the trabecular meshwork at the angle, so the eye pressure spikes suddenly.

Sometimes, glaucoma can be traced to a known cause, such as ocular trauma, inflammation, tumor, advanced cataract, or diabetes.

Who is at Risk for Glaucoma?

• Intraocular pressure
• Age
• Family history
• Ethnic ancestry
• Nearsightedness or Farsightedness
• Past eye injury
• Other ocular conditions
• Other Medical conditions

How is Glaucoma Diagnosed?

Glaucoma is diagnosed through a series of specialized tests that evaluate eye pressure, optic nerve health, and overall visual function.

• Tonometry measures the intraocular pressure (IOP) inside the eye. Elevated IOP is a major risk factor for glaucoma.
  

• Optic nerve imaging uses advanced technology to capture detailed images of the optic nerve, helping detect early signs of damage.

• Visual field testing assesses peripheral vision to identify blind spots that may be caused by glaucoma-related nerve damage.
  

Because glaucoma often develops without noticeable symptoms in its early stages, regular comprehensive eye exams are essential—especially for individuals over age 40 or those with risk factors such as family history, diabetes, or high eye pressure. Early detection through routine screenings is key to preventing vision loss.

University Ophthalmology Associates has expert ophthalmologists in Chicago who can test and diagnose you for glaucoma. 

Treatment Options for Glaucoma

Fortunately, glaucoma is highly treatable. The key to preventing serious vision loss or blindness from glaucoma is early detection. An annual, fully dilated eye examination by your ophthalmologist (Eye MD) is recommended.

Treatment involves medications, laser procedures, and/or surgery to lower internal eye pressure by opening drainage passageways for the trapped fluid. A complete annual eye exam is the best and earliest means to detect glaucoma.

In the early stages of open-angle glaucoma, medicated eye drops are usually prescribed to lower the eye’s pressure. If the condition worsens, a laser procedure called trabeculoplasty is sometimes performed to lower pressure further.

The treatment for angle-closure glaucoma, or narrow-angle glaucoma, is generally initiated with laser iridotomy to open the drainage channels of the eye.