September 17, 2009 in Nation/World

Tooth implant restores sight

Woman was blind 9 years
Fred Tasker McClatchy
 
McClatchy photo

Sharron “Kay” Thornton, who received a rare surgery to restore her sight, talks about seeing again with Dr. Victor L. Perez.McClatchy
(Full-size photo)

MIAMI – A 60-year-old woman, blind for nine years, has regained useful vision following a rare operation in Miami in which surgeons removed one of her teeth, drilled a hole in it, inserted a plastic lens into the hole and implanted the tooth-lens combination into her eye. It’s the first such operation in the United States, they said.

With 20/70 vision now, Sharron “Kay” Thornton, of Smithdale, Miss., can recognize faces and read a newspaper with a magnifying glass, and should get better vision once she is fully healed and fitted with glasses, doctors say.

“We’re excited. We believe a lot of patients can benefit from this,” said Dr. Victor Perez, cornea specialist at Bascom Palmer Eye Institute of Miami, where the procedure was performed.

Thornton lost her vision nine years ago to Stevens-Johnson Syndrome, a severe allergic reaction to medication that blistered and scarred her cornea, the convex part of the eye that covers the iris and pupil. She wasn’t a candidate for a corneal transplant or an artificial plastic lens because the eye was too badly damaged, Perez said. A stem cell procedure attempted six years ago at Bascom Palmer also failed.

Then she was referred to Perez, who also is an associate professor of ophthalmology at the University of Miami Leonard M. Miller Medical School, for what he calls a “procedure of last resort.” He recently trained in Rome under Italian ophthalmologist Giancarlo Falcinelli, who had developed a modified version of the tooth-lens procedure invented by another Italian doctor, Benedeteo Strampelli.

Strampelli developed the procedure in 1963, but it didn’t catch on for decades because of serious complications at one point, including the tooth-lens combination falling out of a patient’s eye.

But with Falcinelli’s modification, the procedure is spreading in Europe and Japan, and, now, in the United States. In Ireland, a worker’s sight was restored after his cornea was destroyed by red-hot liquid aluminum in an explosion at a recycling plant.

The procedure is called a modified osteo-odonto-keratoprosthesis.

Outside experts agree the operation is a first in the United States, and they respect the procedure in the proper patients.

“It can be argued that this is suitable for the most severe of cases, in which the patient has completely dry eyes,” said Dr. Claes Dohlman, cornea specialist at the Massachusetts Eye and Ear Infirmary, a teaching hospital of Harvard Medical School. “In those cases, (the procedure) has a reputation for long-term stability.”

In the Miami operation, Thornton’s eyetooth was chosen because it had a good amount of jawbone and ligament attached, which are crucial for it to stay alive and heal into the eye after being implanted, Perez said. The eyeteeth – sometimes called canines – get their name because they sit in the mouth directly beneath the eyes.

The multistage procedure began when Dr. Yoh Sawatari, a dental surgeon at the University of Miami/Jackson Memorial Medical Center, extracted Thornton’s eyetooth, shaved it flat horizontally, drilled a hole in it and inserted an acrylic lens. He implanted the tooth/lens prosthesis under the skin beneath the clavicle at the top of her shoulder where the combination could heal together for three months.

Meanwhile, an eye surgeon removed scar tissue lining her damaged cornea.

A month later, surgeons removed a patch of skin from the inside of her cheek and laid it over her cornea to replace the moist tissue lost to the disease.

Two months after that, Perez extracted the tooth-lens combination from Thornton’s shoulder, cut a flap out of the skin over the center of her cornea, cut a hole down into the eye and inserted the tooth-lens. He sewed the flap shut to hold in the prosthesis and cut a tiny hole so the lens can protrude a couple of millimeters out of the eye.

On Labor Day weekend, bandages were removed; Thornton was able to recognize faces within two hours.

Thornton now is looking forward to seeing her three grown children and nine grandchildren for the first time in nine years.

Perez believes the patient’s prognosis is good.

“If there isn’t any infection, I’m optimistic we can preserve at least 20/70 vision for the next 10 years.”

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