Glaucoma Symptoms and Causes
Glaucoma is a group of eye diseases affecting the optic nerve, the transmission cable which sends images to the brain. It can affect patients of all ages, although its occurrence in children in unusual.
There are several kinds of glaucoma.
- Open-angle glaucoma. With this most common type of glaucoma, the fluid that normally flows through the pupil into the anterior chamber of the eye cannot get through the filtration area to the drainage canals, causing a build-up of pressure in the eye. Nearly 3 million Americans — half of whom do not know they have the disease — are affected by glaucoma each year.
- Low-tension or normal-tension glaucoma. This type of glaucoma presents optic nerve damage and narrowed side vision.
- Angle-closure glaucoma. The fluid at the front of the eye cannot reach the angle and leave the eye because the angle becomes blocked by part of the iris. This results in a sudden increase in pressure and is generally a medical emergency, requiring immediate treatment to improve the flow of fluid.
- Childhood glaucoma. A rare form of glaucoma that often develops in infancy, early childhood, or adolescence. Prompt medical treatment is important in preventing blindness.
- Congenital glaucoma. A type of childhood glaucoma, this occurs in children born with defects in the angle of the eye that slow the normal drainage of fluid. Prompt medical treatment is important in preventing blindness.
Most people who have glaucoma do not notice any symptoms until they begin to lose some vision. As optic nerve fibers are damaged by glaucoma, small blind spots may begin to develop, usually in the side or peripheral vision. Many people do not notice the blind spots until significant optic nerve damage has already occurred. If the entire nerve is destroyed, blindness results.
One type of glaucoma, acute angle-closure glaucoma, does produce noticeable symptoms because there is a rapid build-up of pressure in the eye. The following are the most common symptoms of this type of glaucoma. However, each individual may experience symptoms differently. Symptoms may include:
- Blurred or narrowed field of vision
- Severe pain in the eye(s)
- Haloes (which may appear as rainbows) around lights
The symptoms of acute angle-closure glaucoma may resemble other eye conditions. Consult a physician for diagnosis immediately if you notice symptoms, as this type of glaucoma is considered a medical emergency requiring prompt medical attention to prevent blindness.
The cause of glaucoma depends on which category the condition falls into.
- Primary glaucoma cannot be contributed to any known cause or risk factor.
- Secondary glaucoma develops as a complication of another medical condition or injury. In rare cases, secondary glaucoma is a complication following another type of eye surgery.