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Types of Glaucoma
Risk Factors

Types of Glaucoma

There are several forms of glaucoma. The most common are:


Open-angle glaucoma – The drainage structure of the eye is located at the “angle” where the iris (the eye structure that distinguishes eye color) and the cornea (the clear window of the eye) meet. For an individual with open-angle glaucoma, the angle appears to be open, but does not function normally. The resistance to fluid drainage is high, thus leading to an increase in IOP. This chronic condition is the most common form of glaucoma.


Angle-closure glaucoma – In individuals whose eyes have a narrow angle, the iris can block the drainage structure, leading to ”angle closure.” The fluid in the eye becomes trapped at the angle, thus, leading to an increase in IOP. Angle-closure glaucoma may be acute (sudden), intermittent, or chronic (developing over a long time). Acute angle-closure glaucoma is a medical emergency and must be treated immediately to prevent visual loss or complete blindness.


Normal tension glaucoma – In patients with this form of the disease, the optic nerve becomes damaged, even though the IOP remains within normal ranges. The optic nerve in the eyes of these individuals are presumably more vulnerable to pressure or to other causes of damage. This form of glaucoma is less understood than the other types. Since IOP appears to be a poor gauge for the assessment of this form of glaucoma and to our understanding of the progression of disease in these patients, imaging studies are more important than ever in the management of these cases.