A tooth for an eye: taking a bite out of blindness

This article was originally on a blog post platform and may be missing photos, graphics or links. See About archive blog posts.

Lending a whole new meaning to the term “eyetooth,” Miami surgeons have implanted a tooth in a 60-year-old blind woman’s eye, using it to anchor an artificial cornea that has restored her vision, lost for nine years. “I’m looking forward to seeing my seven youngest grandchildren for the first time,” said Sharon “Kay” Thornton, who was blinded by Stevens-Johnson syndrome in 2000. The rare, serious skin condition destroys cells on the surface of the eye, causing severe scarring of the cornea that prevents a cornea transplant or use of a conventional artificial cornea. After an attempt to correct her problem using gene therapy failed, Dr. Victor L. Perez of the Bascom Palmer Eye Institute at the University of Miami’s Miller School of Medicine decided to try an unusual procedure called modified osteo-odento-keratoprosthesis that had been developed in Italy but never tried in the United States.

Earlier this summer, Dr. Yoh Sawatari, an oral surgeon at the Miller School, removed one of Thornton’s canine or “eye” teeth--the pointed teeth in the upper jaw, so-named because they sit directly beneath the eyes--and the bone surrounding it. Technicians shaved the tooth and bone and sculpted it to the proper shape, then drilled a hole through it to insert a cylindrical optical lens. The combined tooth and lens were then implanted in Thornton’s shoulder to allow them time to become fully integrated.

Meanwhile, Perez prepared the surface of the eye by removing the scar tissue surrounding the damaged cornea. About a month later, moist skin from inside her cheek was used to cover and rehabilitate the surface of the eye. Two months later, around the beginning of September, Perez removed the tooth from her shoulder and implanted it in Thornton’s eye, carefully aligning it with the center of the retina. A whole was made in the mucosal material from the cheek to allow the lens to protrude through and collect light.

When the bandages were removed from Thornton’s eye on Labor Day weekend, she was able to recognize faces within hours.Now, two weeks later, she is reading newsprint with a visual acuity of 20/70. Doctors expect her vision to continue to improve as the surgical scars heal.

The procedure was originally developed in 1963 by Italian ophthalmologist Dr. Benedetto Strampelli. It was not very successful initially, however, because of serious complications--such as the tooth falling out of the eye. Modifications by Dr. Giancarlo Falcinelli of Italy solved those problems,however, and the procedure is now used in Europe and Japan--albeit rarely. Perez traveled to Rome to learn the technique from Falcinelli.

-- Thomas H. Maugh II