Glaucoma is a complicated disease in which damage to the optic nerve leads to progressive, irreversible vision loss. Glaucoma is the second leading cause of blindness. Glaucoma is actually a group of diseases; the most common type is hereditary.
Most Common Types of Glaucoma
Primary Open-Angle Glaucoma
There are typically no early warning signs or painful symptoms of open-angle glaucoma. It develops slowly and sometimes without noticeable sight loss for many years.
Most people who have open-angle glaucoma feel fine and do not notice a change in their vision at first because the initial loss of vision is of side or peripheral vision, and the visual acuity or sharpness of vision is maintained until late in the disease.
By the time a patient is aware of vision loss, the disease is usually quite advanced. Without proper treatment, glaucoma can lead to blindness. The good news is that with regular eye exams, early detection, and treatment, you can preserve your vision.
Angle-Closure Glaucoma
This type of glaucoma is also known as acute glaucoma or narrow angle glaucoma. It is much more rare and is very different from open-angle glaucoma in that the eye pressure usually rises very quickly.
This happens when the drainage canals get blocked or covered over, like a sink with something covering the drain. Symptoms of angle-closure glaucoma may include headaches, eye pain, nausea, rainbows around lights at night, and very blurred vision.
Normal Tension Glaucoma
Also called low-tension or normal-pressure glaucoma, in normal-tension glaucoma (NTG) the optic nerve is damaged even though the pressure in the eye is not very high.
Those at higher risk for this form of glaucoma are:
- People with a family history of normal-tension glaucoma
- People of Japanese ancestry
- People with a history of systemic heart disease such as irregular heart rhythm