What Is Glaucoma?

Glaucoma is a group of eye conditions that damage the optic nerve — the vital connection between your eye and brain. It is one of the leading causes of irreversible blindness worldwide, yet many people have no symptoms until significant vision loss has already occurred. That's why it's often called the "silent thief of sight."

Types of Glaucoma

There are several forms of glaucoma, but two are most common:

  • Primary Open-Angle Glaucoma (POAG): The most prevalent type. Fluid in the eye doesn't drain efficiently, causing pressure to build gradually over time. Vision loss begins at the periphery and advances inward.
  • Angle-Closure Glaucoma: The iris bulges forward, narrowing or blocking the drainage angle. This can develop slowly or as a sudden, painful attack requiring emergency care.
  • Normal-Tension Glaucoma: Optic nerve damage occurs even when eye pressure is within the normal range. The exact cause isn't fully understood.
  • Secondary Glaucoma: Develops as a result of another condition — such as diabetes, eye trauma, or prolonged steroid use.

Who Is at Risk?

Certain factors increase your risk of developing glaucoma:

  • Age over 60 (risk increases significantly after 40)
  • A family history of glaucoma
  • High intraocular pressure (IOP)
  • African or Hispanic heritage (higher statistical risk)
  • Thin corneas
  • History of eye injury or prolonged corticosteroid use

Recognizing the Symptoms

Open-angle glaucoma, the most common form, typically has no early warning signs. By the time you notice peripheral vision loss, significant nerve damage may have already occurred. Angle-closure glaucoma, by contrast, can cause:

  • Sudden eye pain or pressure
  • Blurred vision or halos around lights
  • Nausea and headache
  • Redness of the eye

If you experience these symptoms suddenly, seek emergency care immediately.

Diagnosis and Testing

Glaucoma is detected through a comprehensive eye exam. Your eye care provider may use several tests:

  1. Tonometry: Measures intraocular pressure.
  2. Ophthalmoscopy: Examines the shape and color of the optic nerve.
  3. Perimetry (Visual Field Test): Maps your full field of vision to detect peripheral loss.
  4. Pachymetry: Measures corneal thickness, which affects IOP readings.
  5. Optical Coherence Tomography (OCT): Creates detailed images of the optic nerve and retinal layers.

Treatment Options

While glaucoma-related vision loss cannot be reversed, treatment can slow or halt its progression:

  • Eye drops: The most common first-line treatment. They either reduce fluid production or improve drainage.
  • Oral medications: Sometimes prescribed alongside drops.
  • Laser therapy (SLT or ALT): Improves fluid outflow through the drainage angle.
  • Surgery (trabeculectomy or drainage implants): Creates a new drainage pathway when other treatments aren't sufficient.

The Importance of Regular Eye Exams

Because glaucoma has no early symptoms, regular comprehensive eye exams are your most powerful tool for early detection. Adults over 40 — especially those with risk factors — should have their eyes examined every 1–2 years. Early detection means more options and better outcomes.

Bottom line: Glaucoma is manageable when caught early. Don't wait for symptoms. Schedule a comprehensive eye exam and ask your eye care provider about your personal risk factors.