Glaucoma is a relatively common, but serious eye disorder and a leading cause of blindness in the U.S. and abroad. The risk factors for glaucoma include a genetic or family history of the disease, advanced age, previous eye injuries and trauma, diabetes and nearsightedness. If undetected or left untreated, it can lead to retinal and optic nerve damage and permanent vision loss. Nearly three million Americans have glaucoma –120,000 of whom are blind due to the condition. The number of cases is projected to rise to about 3.6 million by 2020.
There are two main types of glaucoma – open-angle glaucoma and closed-angle glaucoma. In both situations, the clear fluid in eyes – called aqueous humor – drains too slowly and builds up, causing increased eye pressure.
Open-angle glaucoma has been labeled as the “silent thief of sight” because it is a chronic condition that typically occurs over time, with no accompanying warning signs, pain or symptoms.
In closed-angle glaucoma, the iris of the eye blocks the drainage angle where aqueous humor flows out of the eye. When the drainage angle is suddenly blocked, eye pressure rises rapidly, causing an acute glaucoma attack, a serious condition that can cause blindness within hours.
Less common forms of glaucoma include normal-tension glaucoma, where the eye pressure has a normal reading, but optic nerve damage and vision loss still occur; congenital glaucoma, a hereditary condition that affects infants and children; secondary glaucoma, which forms as a result of another eye issue, another disease like diabetes, a tumor, or long-term steroid use.
Approximately 50 percent of all individuals with glaucoma do not know they have it. Therefore, regular comprehensive eye exams by an optometrist are the best preventive measure to detect and treat the disease early on. Ophthalmologists may use a visual field test to assess if there are any blank spots in your vision that may indicate possible optic nerve damage.
Your eye doctor also may use the term “glaucoma suspect” which means you may have some red flags in at least one eye that should be monitored routinely. Discuss any questions and new information with your eye doctor if you’re concerned about your glaucoma risk.