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Glaucoma Causes
What causes glaucoma?
The exact cause of glaucoma is not known. Experts think that increased pressure in the eye (intraocular pressure) may cause the nerve damage in many cases. But some people who have glaucoma have normal eye pressure.
Open-angle glaucoma
In open-angle glaucoma (OAG), fluid in the eye (aqueous humor) doesn't drain well. When this happens, the fluid builds up. This buildup increases the intraocular pressure (IOP) and may damage the optic nerve.
Up to half of the people with OAG don't have higher-than-normal IOP. This is called normal- or low-tension glaucoma.
Closed-angle glaucoma
In closed-angle glaucoma (CAG), fluid can't drain because the drainage angle is blocked. This may happen when:
- The colored part of the eye (iris) and the lens block the movement of fluid between the chambers of the eye. The blocked fluid causes pressure to build up in the eye and makes the iris press on the eye's drainage system (trabecular meshwork). The increased pressure can cause damage to the optic nerve, leading to vision loss and possible blindness.
- You have a defect in your iris or another problem that causes the iris to fall forward and block the drainage angle.
- You have scar tissue between the iris and the cornea, and it blocks the eye's drainage system.
Congenital and infantile glaucoma
Glaucoma that a baby is born with (congenital glaucoma) or that develops in the first few years of life (infantile glaucoma) is often caused by certain birth defects. A birth defect may happen because of an infection in the mother during pregnancy, such as rubella. Or it can happen because of an inherited condition such as neurofibromatosis.
Secondary glaucoma
Some people get glaucoma after an eye injury or after eye surgery. A cataract and some medicines (corticosteroids) that are used to treat other diseases may also cause glaucoma. Glaucoma caused in these ways is called secondary glaucoma.
Clinical Trials
Clinical trials are research studies that evaluate a new medical approach, device, drug, or other treatment. As a Stanford Health Care patient, you may have access to the latest, advanced clinical trials.
Open trials refer to studies currently accepting participants. Closed trials are not currently enrolling, but may open in the future.