Forget about an eye for an eye -- doctors in Florida have taken a blind woman's tooth, and used it to help restore her vision.
A team of specialists at the University of Miami Miller School of Medicine announced Wednesday that they are the first surgeons in the United States to restore a person's sight by using a tooth. The procedure is formally called modified osteo-odonto-keratoprosthesis (or MOOKP).
Sharron "Kay" Thornton, 60, went blind nine years ago from a rare disorder called Stevens-Johnson syndrome. The disorder left the surface of her eyes so severely scarred she was legally blind. But doctors determined the inside of her eyes were still functional enough that she might one day see with the help of MOOKP.
"This is a patient where the surface of the eye is totally damaged -- no wetness, no tears," said Dr. Victor L. Perez, the ophthalmologist at the Bascom Palmer Eye Institute at the University of Miami who operated on Thornton. "So we kind of recreate the environment of the mouth in the eye."
The three-phase operation started with University of Miami dentist, Dr. Yoh Sawatari, who removed a tooth from Thornton's mouth and prepared an implant of her own dental tissue for her most severely damaged eye. The tissue would be used to make a new cornea to replace the damaged one.
Doctors then removed a section of Thornton's cheek that would become the soft, mucus tissue around her pupil. Finally, Perez and his team implanted the modified tooth -- which had a hole drilled through the center -- to support a prosthetic lens.
"We use that tooth as a platform to put the optical cylinder into the eye," explained Perez.
Perez said doctors often use less risky and less invasive techniques to replace corneas, but the damage from Thornton's Stevens-Johnson syndrome ruled those out.
Using a tooth might sound strange, but it also offers an advantage. Because doctors used Thornton's own cheek and tooth tissue she faces less risk that her immune system will attack the tooth and reject the transplant. Patients getting a cornea transplant from a deceased donor, on the other hand, face chances that their immune system will reject the new tissue.
This Labor Day, Thornton was able to take off the bandages and she immediately saw the light.
"From the first day, she's been able to see 20/70," said Perez. "She cannot drive legally (yet), but she can see her hands, see TV, see the sky, see the clouds."
At the moment, Thornton has nothing covering the cheek tissue on her eye, an aesthetic drawback MOOKP patients must face.
"Her eye looks different but, the goal is once she heals more we can put on a cosmetic eye shield," said Perez.
The technique was developed in Italy in the early 1960s, but the original procedure has been modified over the years by doctors in Europe. Hundreds of people in Japan, England and Italy have regained vision through the technique, but most eye specialists in the U.S. don't foresee MOOKP catching on in America.
"It's a complicated and rare procedure that a few people use in desperate situations [and] some patients benefit when the alternative is blindness," said Dr. Stanley Chang, an ophthalmologist at the Columbia University Medical Center in New York City.