Though all glaucoma is caused by increased pressure in the eye, different types of the condition can yield different symptoms and levels of severity. Below are descriptions of some of the most common types of glaucoma.
The most common type of glaucoma affecting our Phoenix, Arizona, patients is called chronic glaucoma, or primary open-angle glaucoma (POAG). In a normally operating eye, fluid called aqueous humor continually flows through the eye, eventually exiting through tissue known as the trabecular meshwork. In an eye affected by chronic glaucoma, this meshwork becomes blocked or clogged and fluid is unable to flow out of the eye. Intraocular pressure increases, pushing against the optic nerve and causing peripheral vision loss.
Angle-closure glaucoma, or narrow-angle glaucoma, occurs suddenly and presents symptoms such as headaches, eye pain, haloes around lights, and nausea. This type of the disease occurs when fluid in the eye is suddenly kept from draining properly due to blockage or over-dilated pupils. Though symptoms may disappear, it is essential that you seek medical treatment as soon as possible. Each renewed attack destroys more of your sight.
Mixed Mechanism Glaucoma is a combination of narrow angles, or a decrease in space between the cornea and iris, and a clogged drainage system as in Open-Angle Glaucoma. This type of glaucoma may be the result of injury or disease.
Normal Tension Glaucoma is a type of Open-Angle Glaucoma. Although pressures in the eye are within normal limits, optic nerve damage still occurs. This nerve damage results in vision loss, so the pressures must be lowered below normal levels to prevent further damage.
Secondary Glaucoma results from complications from an existing condition such as inflammation, injury, tumors, certain drug usage, diabetes, and advanced cataracts.
Pigmentary Glaucoma develops when particles of the iris break off into the clear fluid inside the eye. These tiny granules flow into and gradually block the drainage system, causing the eye pressure to rise.
Congenital Glaucoma occurs at birth from incorrect or incomplete development prenatally. This condition is very rare.
Exfoliative Glaucoma occurs when particles from the outermost layer of the lens flake off. These flakes collect in the space between the iris and the cornea, eventually clogging the drainage system of the eye and increasing the pressure. This is most common among people of Scandinavian descent.
Neovascular Glaucoma is caused by abnormal formation of new blood vessels in or near the drainage canals. These new vessels block the drainage canals. These new vessels block the drainage channels and prevent the fluid from cycling into the blood stream. This is a form of Open-Angle Glaucoma. This new development of vessels is associated with other conditions, especially diabetes.
Uveitic Glaucoma arises from swelling of the uvea, the middle layer of the eye that supplies blood to the retina. Increased pressure associated with this glaucoma may be caused by the steroid medications treating the inflammation or the inflammation itself.
Traumatic Glaucoma may develop immediately following an injury or can develop over time. Blunt injuries that bruise the eye can cause Traumatic Glaucoma as well as penetrating injuries.