Primary open-angle glaucoma: Causes, risk factors, and symptoms

primary open-angle glaucomaPrimary open-angle glaucoma can begin with no warning signs, so it is often referred to as the “silent thief of eyesight.” This is a chronic form of glaucoma which gradually reduces vision. Without a routine eye exam, this eye problem can very easily be overlooked, leading to vision loss eventually.

What makes primary open-angle glaucoma difficult to spot is that aside from not presenting symptoms, it doesn’t show any abnormalities either.

Causes and risk factors for primary open-angle glaucoma


Primary open-angle glaucoma is caused by an imbalance in the production and drainage of the aqueous humor. This is the fluid that fills the anterior chamber of the eye. If there’s too much of this fluid produced and it is not well drained, then it can raise the pressure inside the eye – known as intraocular pressure (IOP) – to dangerous levels.

As eye pressure increases, it begins to push up against nerve fibers of the optic nerve, which is responsible for sending signals and information to the brain. As a result, there isn’t enough oxygen and nutrients reaching the optic nerve. Slowly but surely, high IOP causes irreversible damage contributing to vision loss.

Vision loss in primary open-angle glaucoma typically begins in the peripheral vision and then moves slowly to central vision.

Risk factors for primary open-angle glaucoma include being of older age, having certain medical problems like diabetes, being extremely nearsighted, having a previous eye surgery, having eye abnormalities, being African-American, having a family history of glaucoma, and living an unhealthy lifestyle (which includes being sedentary and eating poorly).

Signs and symptoms of primary open-angle glaucoma

As mentioned, primary open-angle glaucoma often starts off without presenting any symptoms. It is not until the disease progresses that patients start noticing changes to their vision or any problems.


At first, patients may experience peripheral vision loss or start noticing blind spots.

In order to reduce your risk of complications resulting from primary open-angle glaucoma, you should undergo regular eye exams so that your eye doctor can spot any changes to your eyes early on.