Canadian doctors perform rare surgery to implant a tooth containing a lens into a 33-year-old patient's eye, helping him regain his sight.

Brent Chapman has been blind in both eyes since he was 13 due to Stevens-Johnson syndrome, a rare autoimmune reaction after taking a dose of ibuprofen. Over the past 20 years, he has had 50 surgeries, all to restore his vision. The surgeries have given him some vision, but the effectiveness has diminished over time. Chapman's vision returns after a few years, even months.

Earlier this year, doctors suggested a strange procedure that uses his own tooth to implant into his eye. The procedure is somewhat "unthinkable," but has restored vision to patients around the world for decades.

"This is a rare type of surgery, little known even to ophthalmologists," said Dr. Greg Moloney, an ophthalmologist and surgeon at Mount Saint Joseph Hospital in Vancouver.

The procedure, called osteo-odonto keratoprosthesis (OOKP), uses the patient's own teeth to create a supporting structure for an artificial cornea.

Chapman's surgery, which took place on March 1, was divided into two parts. First, Moloney and his surgical team extracted one of the patient's teeth, filed it down into a rectangle, drilled a hole and placed a plastic optical lens inside. The tooth was then placed temporarily in his cheek for three months.

"The tooth has no connective tissue, so we can't thread it to the eyeball. So implanting it in the cheek for three months gives it a layer of tissue to support it," Moloney explained.

Next, Dr. Moloney removed the sclera - the top layer of Chapman's eye - and replaced it with a soft tissue graft from inside the patient's cheek. The tissue will heal over several months, supporting the implant.

Moloney said the initial procedure went smoothly, and Chapman will be closely monitored over the next few months. When it's time for the second surgery, the surgical team will remove the tooth from his cheek and place it in his eyeball. Moloney and other doctors will pull the tissue out of the eye, remove the damaged iris and lens, and then sew the tooth (with the new optical lens) into the eye. The tissue is then sewn over, leaving a small hole for the lens to pass through. The end result is a pink eye with a small black circle, and the patient's vision restored.

"It sounds strange to have a tooth implanted in the eye, but it's actually a good fit. Teeth contain dentin, which is the ideal tissue to hold a plastic lens without the body rejecting it," Moloney explained, adding that the cheek tissue can recognize the tooth, making the whole procedure go smoothly.

However, the procedure does have risks. All eye surgeries carry the risk of infection, which can lead to complete loss of vision. This type of surgery is often a last resort for people who have lost their sight in the cornea at the front of their eyes due to conjunctival scarring. Scarring can result from autoimmune diseases, chemical burns, and other injuries.

The procedure has restored vision to patients in at least 10 countries, with a high success rate. A 2022 study in Italy found that 94% of patients were still able to see 27 years after surgery. Dr Moloney himself has performed seven successful tooth-to-eye surgeries in Australia.

Chapman hopes the surgery can help him see clearly again. When his doctor first suggested a tooth-to-eye transplant, he was hesitant. However, after talking to a woman in Australia who had undergone the same procedure, he was convinced.

“She was completely blind for 20 years. Now she can go skiing,” he said.

Chapman is one of six patients in the trial at Mount Saint Joseph Hospital. If the surgery goes well, Dr. Moloney and his colleagues plan to ask Health Canada for funding to open the country’s first OOKP clinic.