What do blue and yellow colors have to do with glaucoma?
Both are elements of a new field vision test called SWAP -- short wave-length autoperimetry -- that makes it possible to diagnose glaucoma three to four years earlier than with older tests.
According to Dr. John McGreal, director of the Missouri Eye Institute in St. Louis, this color combination works for detecting glaucoma in eight out of 10 patients.
For decades, the standard test for glaucoma was measuring the eye's pressure. But it is now known that only 20 percent of people with a high pressure reading have glaucoma, McGreal said. The others have ocular hypertension. And to make matters more confusing, 30 percent of people with glaucoma have normal pressure readings.
SWAP works well as the definitive diagnostic tool because it picks up changes in a person's side vision extremely early. McGreal delivered a SWAP presentation at the annual meeting of the American Optometric Association.