What Is Glaucoma?
Glaucoma is a group of eye diseases that damage the optic nerve — the critical connection between your eye and your brain. This damage is most often associated with elevated pressure inside the eye (intraocular pressure), and it can lead to permanent, irreversible vision loss if not caught and managed early.
It is sometimes called the "silent thief of sight" because the most common form, open-angle glaucoma, causes no pain and no noticeable symptoms in its early stages. By the time a person notices vision changes, significant damage may already have occurred.
Types of Glaucoma
Primary Open-Angle Glaucoma (POAG)
The most common form, accounting for the majority of glaucoma cases. The drainage channels in the eye become less efficient over time, causing a gradual rise in intraocular pressure. Peripheral (side) vision is typically lost first, often without the person realizing it.
Acute Angle-Closure Glaucoma
This is a medical emergency. The iris suddenly blocks the eye's drainage angle, causing a rapid, severe spike in eye pressure. Symptoms include sudden eye pain, headache, nausea, blurred vision, and halos around lights. Immediate medical attention is critical.
Normal-Tension Glaucoma
Optic nerve damage occurs even when intraocular pressure is within the normal range. The exact cause isn't fully understood but may relate to poor blood flow to the optic nerve.
Secondary Glaucoma
Caused by another condition or injury, such as trauma, inflammation, steroid use, or certain medications that raise eye pressure.
Who Is at Risk?
While anyone can develop glaucoma, certain factors increase your risk:
- Being over age 60 (or over 40 for those of African or Hispanic descent)
- A family history of glaucoma
- Elevated intraocular pressure
- Thin corneas
- Diabetes, high blood pressure, or heart disease
- Previous eye injury
- Long-term use of corticosteroid medications
How Is Glaucoma Diagnosed?
Glaucoma can only be reliably diagnosed through a comprehensive eye exam. No single test is definitive; diagnosis typically involves several evaluations:
- Tonometry: Measures intraocular pressure.
- Ophthalmoscopy: Examines the shape and color of the optic nerve.
- Perimetry (visual field test): Maps your complete field of vision to detect gaps or losses.
- Gonioscopy: Inspects the drainage angle of the eye.
- Pachymetry: Measures corneal thickness, which affects pressure readings.
- OCT imaging: Creates detailed images of the optic nerve and retinal nerve fiber layer.
Treatment Options
Glaucoma cannot currently be cured, and vision already lost cannot be restored. However, treatment can halt or significantly slow progression.
Eye Drops
Most glaucoma treatment begins with prescription eye drops that either reduce fluid production in the eye or improve drainage. Consistency is essential — missing doses can allow pressure to rise and damage to progress.
Laser Therapy
Laser trabeculoplasty is a common outpatient procedure that improves drainage in the eye. It's often used when drops aren't sufficient or when a patient has difficulty managing daily eye drops.
Surgery
When other treatments don't adequately control pressure, surgical options such as trabeculectomy or micro-invasive glaucoma surgery (MIGS) may be recommended to create a new drainage pathway or implant a drainage device.
Living with Glaucoma
With proper monitoring and treatment, the majority of glaucoma patients retain functional vision throughout their lives. Regular follow-up appointments are essential — your doctor needs to monitor your intraocular pressure, optic nerve health, and visual field over time to ensure treatment is working.
The single most important thing you can do? Get regular comprehensive eye exams. Glaucoma caught early is far more manageable than glaucoma caught late.