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An eyetooth for an eye: A rare transplant restores sight to blinded woman

tooth transplant for cornea cure blindnessA 60-year-old Mississippi woman who had been blind for nine years can now see again after doctors implanted one of her teeth into her eye—the first time the surgery had been performed in the U.S. Two weeks after several sessions of intensive surgery, she now has 20/70 vision in one of her eyes, which is predicted to continue improving as it heals.

In 2000, Sharon Thornton was diagnosed with Stevens-Johnson syndrome, a rare disease that can destroy skin—and corneal—cells. Even after she recovered from the disease, brought on by a reaction to her medication, her corneas—the surface of the eye—were too scarred to allow her to see, or obtain a transplant.

After stem cell treatment in 2003 failed to restore her vision, doctors went looking for alternatives. Victor Perez, an associate professor of ophthalmology at the University of Miami Bascom Palmer Eye Institute, decided to attempt modified osteo-odonto keratoprosthesis (MOOKP), what he called a procedure "of last resort," in a prepared statement

To begin the months-long process, doctors removed one of Thornton's canine teeth—aka an eyetooth—along with part of the jaw and cut it all down to a shape small enough to replace the cornea. The doctors then drilled a hole into it to insert a lens. In order for the tooth to bind to the lens sufficiently, the implant spent a couple months in the patient's body. In Thornton's case, it was implanted near her shoulder.  

To prep the eye to receive the tooth and lens, the doctors placed a cheek graft over the eye to promote moisture. The final tooth-lens product was removed from Thornton's shoulder and placed in the center of the eye, in line with the retina.

The MOOKP procedure was developed in Italy in 1963, and has been more common in Europe and Asia, but only about 600 operations have been undertaken. Given the small number of treatments, its safety remains unconfirmed, and other doctors have their reservations. "It requires a sizable team and several operations," Ivan Schwab, of the American Academy of Ophthalmology, told CNN. "It's just an extreme variation on techniques we're already doing."

The procedure also requires the cheek tissue graft to remain over the eye surface, which gives it a strange, skin-like appearance. Doctors, however, can often use a cosmetic eye shell to make it look more natural.

For some, however, the procedure might represent a new chance at vision. Even in patients who qualify for a corneal transplant, the body occasionally rejects the foreign tissue. Using a piece of the person's own body makes it more likely to accept the necessary lens. 

After a patch was removed from her eye on Labor Day, Thornton could begin to make out faces for the first time since 2000. She later told CNN that she was looking forward to being able to see her newest grandchildren for the first time—and being able to watch her favorite TV show again: Operation Repo.

 

Image courtesy of Wikimedia Commons/NIH National Eye Institute

 

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