Glaucoma Causes

Glaucoma is a silent disease with no symptoms and no warning signs. By the time it has advanced, you may have lost significant vision. In this article, the Eye Consultants of Pennsylvania will explore glaucoma causes in detail.

What Is Glaucoma?

Over time, an internal buildup of eye pressure causes glaucoma. Eventually, loss of sight occurs as a result. There are two common forms of glaucoma: primary open-angle glaucoma and angle-closure glaucoma.

Open-Angle Glaucoma

This form of glaucoma is referred to as “open-angle,” referring to the angle in the eye where the iris meets the cornea. Over time, the eye’s natural drainage canals become clogged, and that causes internal eye pressure to buildup, which then damages the optic nerve. Open-angle glaucoma affects about four million Americans annually, and is by far the most common form of glaucoma.

Open-angle glaucoma progresses slowly; it usually has no warning signs or symptoms. Patients can have glaucoma for several years without noticing any significant vision loss. Patients don’t really notice very pronounced changes in vision because the first vision to be lost is usually peripheral (side) vision. Furthermore, visual sharpness (visual acuity) does not decline as glaucoma progresses, and this makes it even more difficult to notice any problems.

By the time most patients notice any marked vision loss, open-angle glaucoma has usually progressed to an advanced stage. Unfortunately, doctors cannot restore any vision loss that has already occurred, even with surgery.

For these reasons, the importance of regular eye exams cannot be stressed enough. Regular exams are the only way that doctors can detect the characteristic optic nerve damage and vision degradation that are the two main indicators of glaucoma. While you may not notice symptoms, doctors can detect glaucoma’s early signs and move proactively to a treatment to protect your vision.

Closed-Angle Glaucoma

A much rarer form of glaucoma, called closed-angle glaucoma, develops quickly, usually in only one eye. Contrary to the open-angle form, you will definitely notice the symptoms of closed-angle glaucoma: sudden severe eye pain, headache, nausea or vomiting, sudden loss of vision in one eye, sudden blurred or hazy vision, halos or rainbows around lights, and redness of the eye.

If you experience any of these symptoms, seek immediate emergency room medical attention. These symptoms may not mean you have this form of glaucoma, but they are certainly signs of a potentially serious problem.

What Causes Glaucoma

Glaucoma occurs when the eye fails to maintain a balance between eye fluid that drains and eye fluid that remains internal to the eye (called intraocular fluid). The eye does need some internal fluid pressure to retain its shape so that you can see properly. However, a buildup of intraocular pressure is detrimental because the eye cannot automatically relieve pressure or “deflate.” Therefore, internal eye pressure keeps rising, eventually pressing on the optic nerve and causing damage. Over time, the nerve fibers suffer permanent damage and you suffer vision loss.

Glaucoma can also occur when eye pressure is normal but the optic nerve is highly pressure-sensitive. The nerve fibers suffer irreversible damage, even with normal pressure. Some research shows that this type of glaucoma might be caused by decreased blood flow to the optic nerve, perhaps due to a narrowing of blood vessels that typically provide nourishment to the optic nerve.

Poor blood flow inside the eye can cause blind spots (called scotomas) that develop in a person’s visual field.

Why Screening Is Crucial

Conventional glaucoma screening uses tests that detect high internal eye pressure. However, doctors also do a direct examination of the optic nerve and visual field testing, two other non-conventional but essential tests for diagnosing or ruling out glaucoma.

If you know or suspect you have glaucoma and want to learn more about its causes, or it has just been a while since you’ve had an eye exam, come see our experienced specialists at Eye Consultants of Pennsylvania. Give us a call today at 610-378-8500.