A Tooth for an Eye

Picture a harmless pre-game ritual like taking an ibuprofen before a basketball match, only for it to trigger a severe medical emergency that leaves you with burns across your body and eyes. That was the devastating reality for thirteen-year-old Brent Chapman from North Vancouver, whose life changed forever after a chemical reaction left him in a 27-day coma, ultimately costing him his vision. Countless surgeries followed, including multiple transplants that briefly offered chances of restoring his vision, but each attempt ultimately failed. However, Dr Greg Moloney, an eye surgeon and clinical associate at the University of British Columbia, became the rare hope that Chapman needed. He performed a rare tooth-in-eye implant procedure that finally gave Chapman back what he thought was lost forever: his sight.

In a healthy eye, the cornea, the transparent and dome-shaped protective outer layer, lets incoming light pass through to the lens and then to the retina, a sensitive layer of nerve tissue, which converts light into electrical signals for the brain. But Chapman’s reaction triggered Stevens-Johnson syndrome, which causes severe inflammation leading the immune system to destroy eye limbal stem cells that are responsible for replacing the outer cornea layer. Without this cornea cell renewal, the tissue becomes scarred and eventually permanently opaque, blocking light from entering it, resulting in Chapman’s complete blindness.

With no other treatment options left, Moloney turned to a procedure known as osteo-odonto-keratoprosthesis (OOKP). The canine tooth, the longest tooth in the mouth, is extracted from the mouth alongside a thin layer of surrounding bone to preserve the tooth’s blood supply. The tooth is then shaved into a four-millimetre block, and a hole is drilled through it to support the insertion of a plastic optical cylinder, which is an artificial lens that lets light enter the eye again. The tooth is then implanted into the patient’s cheek for a few months to allow the soft living tissue and blood vessels to grow and integrate around it, reducing the risk of bodily rejection once implanted in the eye. Once the tissue is ready, surgeons cut an opening in the eye to create space for the tooth implant, replacing the previously damaged cornea with it. More cheek tissue is extracted and taken to cover the tooth side of the implant, leaving the lens exposed so light can pass through to the retina, ultimately restoring lost vision.

“It’s like watching people come out of a time capsule and reintroduce themselves to the world. It’s highly emotional for us,” said Dr Greg Moloney, reflecting on the remarkable medical procedure he helped pioneer. The surgery can take over twelve hours and is only performed by a handful of specialists globally, with strong long-term results. In one study, the tooth implants remained anatomically intact in around 94% of total cases. However, the intensity of the procedure requires lifelong monitoring and checkups to ensure the tooth implant does not erode. There have also been reported side effects such as mild glaucoma, an eye disease that damages the optic nerve and can result in vision loss. But this was a risk that Chapman was willing to take.

“What is the first thing you want to do after the surgery?” was a question posed to Chapman in an interview with CNN. “Just see the world and take it all in,” he replied. This extraordinary procedure shows how far modern medicine has advanced in making once-irreversible blindness treatable. Chapman is just one of many patients who can benefit from this. Ultimately, it turns out the solution was hiding in the teeth all along.

Illustration by Ramona Kirkham