Glaucoma is the name for a group of eye diseases that damage the optic nerve and can result in vision loss and blindness. Damage is most often caused by increased pressure in the eye when extra fluid builds up in the anterior chamber. Pressure builds because the channels are blocked and the fluid is not released or is released too slowly (open-angle glaucoma). Another risk factor for optic nerve damage relates to blood pressure. So, it is important to work with your medical doctor to control your blood pressure.
Some cases of glaucoma are not caused by increased pressure, and in those cases, the cause may not be found. It can occur after an injury, after eye surgery, because of poorly controlled diabetes, because of an eye tumor or because the patient is on certain medications for other diseases.
Not every person with increased eye pressure will develop glaucoma. Some people can tolerate higher levels of eye pressure better than others. A certain level of eye pressure may be high for one person but normal for another. And Glaucoma can develop without increased eye pressure. This form of glaucoma is called low-tension or normal-tension glaucoma. It is a type of open-angle glaucoma.
Anyone can develop glaucoma, but some peopleare at higher risk than others. African-Americans over age 40, everyone over age 60 (especially, Mexican-Americans) and people with a family history of glaucoma are particularly vulnerable. A comprehensive dilated eye exam can reveal more risk factors, such as high eye pressure, thinness of the cornea, and abnormal optic nerve anatomy. A Visual Field test measures your peripheral (side) vision and is an important early-diagnosis tool.
Without treatment, people with glaucoma will slowly lose their peripheral (side) vision. As glaucoma remains untreated, people may miss objects to the side and out of the corner of their eye. They seem to be looking through a tunnel. Over time, straight-ahead (central) vision may decrease until no vision remains.
Left: Normal Vision. Right: Vision with Glaucoma
Photos from the National Eye Institute (NEI) website
There is no cure for glaucoma, and vision lost from the disease can’t be restored. But there are treatments that can slow the progression of the disease, which makes early diagnosis absolutely critical. Regular visits to your eye doctor and comprehensive exams and testing are key to early diagnosis.