VOA标准英语2012--Glaucoma, A Stealth Disease And Major Cause of Blindness

（单词翻译）

Glaucoma, A Stealth Disease And Major Cause of Blindness

If you think you are not at risk for glaucoma, think again. Glaucoma is a disease that steals the sight of people around the world -- and they typically don't even know they have the disease until it has permanently¹ destroyed at least 40 percent of their vision.

Dr. Alan Robin² specializes in treating glaucoma.

"It's the leading cause of blindness in the United States. In Hispanics and in African-Americans, it’s the second leading cause of blindness," said Robin.

In China and in India, glaucoma is the second leading cause of blindness.

"The glaucoma you see in sub-Saharan Africa is a much more aggressive, much more blinding disease than the glaucoma we see in Americans or even African-Americans in the United States," he said.

Dr. Eric Fleischer sees these racial differences at Medstar Washington Hospital Center.

"Pretty much anybody who has ancestry³ in Africa has an increased chance for developing glaucoma," said Fleischer.

Age is another risk factor for glaucoma, although people of all ages can get it. As Dr. Robin explains, it's a group of diseases that commonly produce pressure in the eye.

"An eye is sort of like a watch. And behind the face of the watch that has the numbers, fluid is made. It goes through your pupil and into the front of the watch between the numbers or the face and the crystal. There's an area around the edge of the watch that drains the fluid," he said.

When that drain is clogged⁴, the fluid can't leave the eye as fast as it is produced. The rising pressure within the eye damages and eventually kills the optic nerve. The result is blindness.

The process is usually so painless and subtle, people don't notice it.

"Typically they'll notice if they bump into door frames, because they've lost their peripheral⁵ vision, or they'll start having car accidents because they don't see a car to one side or the other," said Fleischer.

Fortunately, glaucoma can be easily diagnosed. The simplest test measures peripheral vision. That's because with glaucoma the side vision is the first to go.

The good news is that, if caught early, glaucoma can be managed.

"It's not preventable, but it's treatable," said Robin.

Glaucoma is not reversible, but, as researchers learn more about it, they grow more hopeful that glaucoma can one day be cured or even prevented.