Pigment studied for ability to block degeneration in eye

ST. LOUIS - Pigments that tint leaves in the fall and give orangepeppers their color are also nestled in the back of the eye. Can theyhelp stop a blinding disease and protect sensitive eyes from brightlights?

Dennis Gierhart is betting they can. He even started a companybased on the faith that supplements containing the pigments canreverse light sensitivity and slow down macular degeneration, theleading cause of blindness in the elderly.

He's commissioned a study at the University of Missouri-St. Louis,where researchers are testing the supplements to see if they trulycan help the health of the eye. Washington University is alsoconducting tests on the pigments and their effect on eye disease.

The impact of the pigments is "speculative" right now, said Dr.Rajendra S. Apte, an ophthalmologist who is leading the WashingtonUniversity study. But macular degeneration is such a problem that, hesaid, "we need whatever we can get."

Macular degeneration, the leading cause of blindness in peopleover 65, happens when light-gathering cells at the back of the eyedie. The earliest stages of macular degeneration are known as the"dry form." About 10 percent of people have a more advanced form,known as the "wet form," for the leaky blood vessels that invade thearea.

There is no approved treatment for the dry form of maculardegeneration. Scientists want to know whether two pigments in the eye- lutein and zeaxanthin - might slow the disease or stop people fromdeveloping it.

The two pigments form a layer over the central part of the retina,called the macula. The pigments don't affect vision directly anddon't filter out ultraviolet rays, but they filter out high-energy,short-wave blue light that can damage the delicate eye tissue.

Both pigments are also antioxidants and may work to keep retinatissue healthy. Some studies have linked low levels of the pigmentsto an increased risk of developing macular degeneration.

The more widely known of the pigments is lutein, a component ofmany multi-vitamins, and nutritionists tout its presence in foodssuch as kale and spinach.

Gierhart thinks it's time attention turned toward zeaxanthin,which is possibly more powerful.

Gierhart, 56, first focused on the pigment when he was a seniorscientist at an agricultural chemical company. He was interested init as a feed additive to color chicken skin yellow. (Americanconsumers prefer yellow chickens, according to marketing studies.)

He went to a scientific meeting about 10 years ago and saw threepresentations that showed the antioxidant pigment is deposited in thecenter of the eye. He was immediately struck with a notion: What ifthe pigment could protect eyes from disease?

He later made himself a human guinea pig for testing dietarysupplements containing the chemical. Every day for six months,Gierhart popped a capsule containing zeaxanthin (pronounced zee-ah-zan-thin). Every week, he gave blood to determine whether the pigmentwas being absorbed correctly.

With his salt-and-pepper hair and dark eyes, Gierhart isn't thesort of person usually considered at risk for macular degeneration,which often hits people with light-colored eyes.

But a measurement of Gierhart's macular pigment showed that he hadprecious little pigment over his retinas. That put him at risk formacular degeneration. Taking the supplements increased the pigmentlevels in his eyes to normal levels.

After a few months, Gierhart noticed that bright lights didn'tbother him as much and he didn't sunburn as easily as he used to.

About six years ago, he came out of retirement to launchZeaVision, a company that sells supplements containing the pigments.So far, the company is selling the pills through about 100 eyedoctors and over the Internet. The pills don't require federalapproval because they are not drugs.

Still, Gierhart's company placed its supplements under scientificscrutiny at the University of Missouri-St. Louis to see if theyreally do what he believes they can.

University of Missouri-St. Louis researchers, led by Carl J.Bassi, director of research for the College of Optometry, areconducting two separate trials of ZeaVision's supplements.

The first tests whether taking the supplements increases the levelof pigment in the back of the eye. The second will determine whetherincreasing the pigment levels can reduce sensitivity to light.