We’re all familiar with eye teeth – also known as canines, they’re named as such because of their alignment under the eyes. They’re usually the teeth that are happily sacrificed for some desired talent or object, as in, “I’d give my eye teeth to be able to play piano like that.” Why they’re the chosen ones is anyone’s guess really; being a brilliant pianist might eventually lose some of its gloss when you have to keep explaining why your smile has two noticeable teeth missing whenever you’re not impressively pounding the ivories.
We’re also familiar with the biblical saying, “An eye for an eye, a tooth for a tooth …” referring to punishment; although apparently it was an Old Testament guide for judges rather than a handy rule for personal revenge. Mahatma Gandhi quite rightly made the later, pragmatic observation that, “An eye for an eye will only make the whole world blind.”
Which indeed it would. It seems we mostly behave like we are, anyway. Or at least extraordinarily near-sighted.
Metaphorically we are. Statistically, we most certainly are.
There’s mounting evidence that myopia is becoming much more prevalent. Whether it be the result of forever peering at screen, or genetics, or changes in food quality it’s estimated that 30% of the global population is currently myopic. Projections are, that by 2050 almost half the world will be nearsighted.
That’s a staggering 5 billion people.
It’ll make EssilorLuxottica SA happy: it already sells almost a billion pairs of glasses a year. Although to be fair, a lot of them are sunglasses. Armani, Chanel, Tiffany & Co, Dolce & Gabbana … you get the drift.
Of course being nearsighted is much more preferable to having no sight at all. It’s unfortunate that there are millions of people who’d attest to that.
Globally, cataracts are the number one cause of blindness. In 2023, more than 94 million people were suffering cataract-related blindness – a number that has increased over the past 30 years. Despite the success of cataract surgery programmes such as the Fred Hollows Foundation that began in 1992 with his determination to end avoidable loss of sight, this non-profit organisation alone now reaches more than 25 countries. It’s clear that population growth and aging are outpacing the benefit of these institutions.
Ophthalmic surgery can correct vision that has been lost or distorted via the likes of cataracts, glaucoma and diabetes related conditions. Of these, the most commonly recognised and performed is LASIK surgery. It improves sight clarity and quality by altering the curvature of the cornea and changing its responsiveness to light.
There is however, severe corneal blindness that cannot be repaired by laser surgery. It is the option of tooth-in-eye surgery, viable as long as the retina and optic nerves have remained intact.
Formally known as osteo-odonto keratoprosthesis (OOKP) this multi-stage procedure creates a prosthetic cornea made predominantly of tooth and soft tissue to prevent the implant being rejected.
As futuristic as it sounds, it’s a procedure that was actually pioneered in the 1960s by Italian ophthalmologist Benedetto Strampelli. Rejection of a foreign body is a major aspect of surgery failures, and for tooth-in-eye surgery this is greatly minimised by reliance on the patient’s own biological material.
One case involves a 33-year-old who had become blind at the age of 13, after an over-the-counter pain medication resulted in an auto-immune reaction that had him comatose with severe burns. Even after some 10 corneal implants over the years, none had permanently restored his eyesight. He was deemed an excellent candidate for one of three patients to have the procedure performed for the first time in Canada.
Teeth contain dentin, the hard tissue under enamel that is ideal housing material in terms of structure and availability for this particular process. Surgeons first extract a tooth – often a canine – which is pared down to a rectangular layer. Called a longitudinal lamina it has a hole drilled in the centre into which a tiny, plastic telescopic lens is inserted. Sewn inside the patient’s cheek, it remains there for a few months until new tissue has formed on its surfaces.
A second surgery removes scarring from the eye, and replaces it with more cheek-harvested healthy cells.
The third, and final operation sutures the tooth and lens implant under the transplanted cheek tissue and into the eye socket. The transplanted flap is laid over the eye to keep this biological composite insert in place.
Sight is regained within a month of the completed surgeries.
Canada now joins Australia, Japan, India, the US, Italy, the UK and Germany as one of less-than-a-dozen countries where this procedure is available. Despite its complexity and potential complications, it has proven a highly successful treatment over the 60 years it’s been performed throughout the world.
A 2022 study of 82 eyes of 59 patients who underwent OOKP surgery between 1969 and 2011, included clinical characteristics prior to the surgery, as well as complications and further surgeries until the end of the recorded follow-up. Visual acuity was assessed preceding the intervention; and then at 1 month, 12 months and every 5 years until the 30th year. It determined that almost three decades after the completed procedure, 94% of participants had maintained their sight – even a patient who had been completely blind for 20 years beforehand.
For patients either ineligible, or for whom corneal transplants have not been successful, tooth-in-eye surgery with its evidenced success monitored for more than 50 years, is an incredible option for restoring vision.
You’d give your eye teeth for that.
