UBC researchers attempt to grow human eye tissue with drugs
Aiden Gibbons was three days old when doctors noticed he was missing something most people take for granted: the coloured ring-shaped membrane behind the cornea of the eye known as the iris. It’s a genetic condition called aniridia that impacts about 5,000 people in North America at birth.
Those living with the defect wear dark contact lenses to limit exposure to light, and require eyeglasses for reading. For Aiden, now an avid soccer player at 11 years old, it also means his eyes are in near constant motion, darting back and forth.
Aniridia causes a progressive loss of vision and increasing ocular pain with age. Doctors say many patients are legally blind by the time they are in their 20s.
But Aiden’s parents say he’s not sitting as close to the television as he used to, a testament perhaps to ground-breaking research underway at the University of British Columbia aiming to replace the missing tissue and restore lost vision by administering a medication.
“Blindness in people can be a severe problem, especially if it is initiated early in their life,” Dr. Kevin Gregory-Evans of the UBC department of ophthalmology and visual sciences told CTV News. “They cannot work. They have difficulty forming social bonds with people. I hope this drug can solve a lot of their problems.”
Aiden is now two years into the trial. The drug he is taking is designed to help the body replace the missing protein responsible for the condition.
A previous therapy trial with mice has given researchers reason to expect positive results. Mice with missing irises because of aniridia saw the damage repaired, and vision restored, without side effects.
“It was such an amazing observation. I didn’t believe it. We had to go back again and again, because we just couldn’t believe that this could have happened,” said Dr. Cheryl Gregory-Evans, who is also leading the research.
The human eye develops until age five, she explains. Conditions like aniridia are like a stop sign that blocks proteins that help the iris develop. The drug gives those proteins a green light to allow full development.
Aiden, along with 34 other young patients involved with the UBC clinical trial, mix a special powder containing the drug into a beverage twice day. Aiden’s parents call him a “pioneer of science.”
“We tell Aiden this is not just about him. Of course we want this for him, but this is also to help other people,” said Aiden’s mother Kishani.
The results of the study will not be known for another year.
Dr. Cheryl Gregory-Evans estimates 12 per cent of all human diseases are caused by the so-called “premature stop codes,” that are behind aniridia. She hopes one day the same pharmaceutical techniques applied in her study will be used on a broader scale.
“If this works for one particular disease then the likelihood (is) it will work for others,” she said.
“It is amazing, it is miraculous,” said Kishani. “It is really quite mind blowing. I mean if you think about it, essentially what Dr. Gregory-Evan says is it is like being born without a hand and taking a medication that will literally regrow that hand.”
With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip