Artificial Eyes Get A New Look

July 17, 1994|By Jonathan Bor | Jonathan Bor,Sun Staff Writer

Along a Pacific atoll, frogmen are swimming past kaleidoscopic schools of fish, undulating plants and spiky sea urchins in search of a drab white boulder made of coral. It's a medical find: the ideal material for an artificial eye.

In an operating room in Baltimore, Dr. Darab Hormozi is implanting a coral ball into a patient blinded in one eye by a nail. Once six muscles are surgically attached, the fake eye will move in tandem with the real one -- even though it can't see a thing.

But the implant won't look real until John J. Kelley Jr., a member of the small fraternity of artisans called ocularists, adds a plastic facade that has all the right aesthetic details -- flecked iris, milky white sclera, even the spidery blood vessels that creep along the margins.

Once that's done, you'll think the prosthesis is looking right through you.

For hundreds of years, European and American craftsmen and scientists tried in vain to fashion an artificial eye that looks and moves like the real thing. The first implant was blown glass. Further attempts were made with silk, wood, cork, gold, aluminum, rubber, sponge, silicone and steel.

The eyes were fine in some respects. They filled the socket, preventing the bony orbit from closing in on itself. Skilled craftsmen, adept with paints and techniques of glass blowing, could give them a natural look. But they were missing something.

They would move, but in a floating, disembodied fashion that would draw unwanted curiosity. In recent years, ophthalmologists have caught on to the wonders of coral -- a material that, because of its microscopic pores and uncanny resemblance to human bone, can be made to move like a puppet on a string.

It can dart from side to side or make wide, sweeping rolls. But Dr. Hormozi, a Baltimore ophthalmologist who has implanted 80 coral balls over the last three years, seems equally impressed with the way the eye shifts almost imperceptibly when someone looks at a stationary object.

"You get that targeting motion that is characteristic of the living eye rather than the dead motion of the dead eye," said Dr. Hormozi, a specialist in ocular plastic surgery at the Greater Baltimore Medical Center and St. Agnes Hospital.

"If you're looking in someone's eye and the eye looks funny, you're not making eye contact. And if you avoid looking at someone's eye, you lose the power of conversation."

Someone who lost an eye in an accident may want a prosthetic eye. So, too, may the person who had an eye surgically removed because of illness, infection or a congenital deformity.

Timothy Prechtel, 22, of Edgemere, had his right eye removed last year because of a painful condition dating to childhood. His problem began when a young playmate tossed a nail that found his eye.

Surgery restored his sight, but a lingering pain grew so intense that doctors eventually had to deaden all sensation -- including sight -- with a chemical injection when he was 13.

Last year at GBMC, Dr. Hormozi removed the eye when it became infected and replaced it with a coral ball. "The old eye was shriveled up, dying," said Mr. Prechtel, a technician for Bethlehem Steel.

A convincing look

For at least a century -- long before coral entered the picture -- the artificial eye has been a two-part device.

The foundation is a ball that's implanted deep in the eye cavity. It is sealed from the outside world inside a tough sac known as sclera, the same tissue that gives the natural eye its "white" on either side of the iris.

If surgeons can't salvage the sclera from the patient's original eye, they obtain it from an eye bank -- a repository of donated tissues used for transplant. Sealing the implant prevents transmission of germs from the environment into the eye cavity.

To give the device a convincing look, ocularists fashion a shell that hugs the sphere the way a contact lens hugs a living eye. The shell -- made for many years of glass, but since the 1940s made of plastic -- is what gives the artificial eye the look of anatomical correctness.

Dr. Arthur Perry, a San Diego ophthalmologist who invented the coral ball, said he was troubled by the artificial eye's immobility when he began seeing patients as a young resident in the mid-1970s.

"People would come in -- their eye would look great, but as soon as they'd move the good eye on the other side, their implant wouldn't look right," he said.

This posed a scientific challenge -- a maddening one.

In most cases, the patient with a blind eye on one side and a seeing eye on the other had functioning muscles in both sockets. The "good" eye supplied the brain with all the visual information it needed to trigger muscles movement in both eyes -- even if the other eye saw nothing.

So when surgeons removed the blind eye, they were left with muscles that were theoretically capable of moving an implant. But the muscles, like the implant itself, had to be sealed inside tissue to prevent infection -- leaving surgeons helpless to bring motion to the outer shell.

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