What are glaucoma tests?Glaucoma tests are a group of tests that help diagnose glaucoma, a disease of the eye that can cause vision loss and blindness. Glaucoma happens when fluid builds up in the front part of the eye. The extra fluid causes an increase in eye pressure. Increased eye pressure can damage the optic nerve. The optic nerve carries information from the eye to the brain. When the optic nerve is damaged, it can lead to serious vision problems.There are several types of glaucoma. The main types are:Open-angle glaucoma, also called primary open-angle glaucoma. This is the most common type of glaucoma. It happens when the fluid in the eye doesn't drain properly from the eye's drainage canals. The fluid gets backed up in the canals like a clogged sink drain that gets backed up with water. This causes an increase in eye pressure. Open-angle glaucoma develops slowly, over a period of months or years. Most people don't have any symptoms or vision changes at first. Open-angle glaucoma usually affects both eyes at the same time.Closed-angle glaucoma, also called angle-closure or narrow-angle glaucoma. This type of glaucoma isn't common in the United States. It usually affects one eye at a time. In this type of glaucoma, drainage canals in the eyes get covered up, as if a stopper was put over a drain. Closed-angle glaucoma can be either acute or chronic.Acute closed-angle glaucoma causes a rapid increase in eye pressure. It is a medical emergency. People with acute closed-angle glaucoma can lose vision in a matter of hours if the condition is not treated promptly.Chronic closed-angle glaucoma develops slowly. In many cases, there are no symptoms until damage is severe.
