Outlook

Worldwide, glaucoma ranks as one of the leading causes of blindness. Even if people with glaucoma do not become blind, vision can be impaired. In developed countries, most people get treatment in time to preserve their vision. Even so, glaucoma causes between 3 - 6% of blindness cases in Caucasian Americans, and even more cases in African Americans. In a 20-year study of Caucasian American patients with glaucoma, blindness in at least one eye occurred in 27% of patients and blindness in both eyes occurred in 9% of patients. The blindness rates in African Americans are most likely higher. In fact, glaucoma is the leading cause of blindness in African Americans. Despite this higher prevalence, this ethnic group receives surgical treatment at half the rate of Caucasian Americans.

Outlook for Primary Open-Angle Glaucoma

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The Process Leading to Vision Loss. Chronic glaucoma is often called “the silent thief of sight," because the afflicted person has no warning sign, no hint that anything is wrong. Untreated, the destruction develops slowly over time:

• Over years or decades, the increased pressure compresses nerves at the back of the eyes.
• Glaucoma gradually destroys first the outer fibers of the optic nerve, which reduces peripheral vision (the top, sides, and bottom areas of vision), but not central vision.
• By the time a person notices that peripheral vision has been lost, permanent damage has already occurred.
• If the eye pressure remains high, the destruction can progress until tunnel vision develops, and the person is only able to see objects that are straight ahead.
• The last nerve fibers destroyed are those responsible for central vision; if this occurs, the glaucoma victim becomes totally blind.