In 2002, Ian Thompson, a specialist in facial reconstruction at King’s College, London, received an urgent phone call. A patient in his late 20s had been struck by an out-of-control car mounting the pavement. The impact had sent him catapulting over the bonnet of the car, smashing his face and shattering the fragile orbital floor – the tiny bone, no more than 1mm thick, which holds the eyeball in place in the skull.
“Without the orbital floor, your eye moves backwards into the skull, almost as a defensive mechanism,” Thompson explains. “But this results in blurred vision and lack of focus. This patient had also lost the ability to perceive colour. His job involved rewiring aircraft and as he could no longer detect a red wire from a blue one, he’d barely been able to work in three years.”
The accident had happened three years earlier. Since then, surgeons had desperately tried to reconstruct the bony floor and push the eye back into position, first using material implants and then bone from the patient’s own rib. Both attempts had failed. Each time, infection set in after a few months, causing extreme pain. And now the doctors were out of ideas.
Thompson’s answer was to build the world’s first glass implant, moulded as a plate which slotted in under the patient’s eye into the collapsed orbital floor. The idea of using glass – a naturally brittle material – to repair something so delicate may seem counterintuitive.
But this was no ordinary glass.
“If you placed a piece of window glass in the human body, it would be sealed off by scar tissue, basically wobble around in the body for a while and then get pushed out,” says Julian Jones, an expert in bioglass at Imperial College London. “When you put bioglass in the body, it starts to dissolve and releases ions which kind of talk to the immune system and tell the cells what to do. This means the body doesn’t recognise it as foreign, and so it bonds to bone and soft tissue, creating a good feel and stimulating the production of new bone.”
For Thompson, the results were immediate. Almost instantaneously, the patient regained full vision, colour and depth perception. Fifteen years on, he remains in full health.
Thompson has gone on to use bioglass plates to successfully treat more than 100 patients involved in car or motorcycle accidents. “Bioglass actually works even better than the patient’s own bone,” Thompson says. “This is because we’ve found that it slowly leaches sodium ions as it dissolves, killing off bacteria in the local environment. So, quite by chance, you have this mild antibiotic effect which eliminates infections.”
By David Cox | BBC
Image Credit: David Cox/BBC