OTTAWA — It was three months after the surgery before Dr. May Griffith got her first good night’s sleep.
An experimental procedure to repair the damaged eyes of 10 patients using artificial corneas had Ottawa scientist Griffith and her colleagues on tenterhooks.
The pioneering endeavour, conceived a decade ago in Griffith’s Ottawa laboratory, offers a gleam of hope for people with eye damage stuck on long waiting lists for corneas that are in such short supply around the world.
“You worry,” Griffith said. “You do everything to make sure that things are safe for patients, but there’s always a worry because it is the first time that this has been tried.”
Those worries gave way to relief as the weeks rolled into months and none of the patients had trouble seeing after the surgery.
Actually, most said they could see better.
Vision improved in six of the 10 patients. The other four could see better when they wore contact lenses.
The nerves and cells grew back fully in nine of the 10 patients. Griffith says one patient’s eyes were slower to take to the surgery, but they are now starting to catch up.
Griffith’s research was published Wednesday in the journal Science Translational Medicine.
The cornea is a thin, clear layer of collagen and cells over the eyeball. It filters light and helps the eye focus.
Having a cloudy cornea is like trying to see through frosted glass. Diseases that cloud the cornea are a leading cause of blindness.
Cornea transplants from human donors can help people with damaged eyes to see again, but the waiting list is long and growing.
An aging population turning to laser-eye surgery to fix their vision is a problem for scientists such as Griffith, who are loathe to use zapped corneas that have lost their original shape and strength.
Elsewhere, cultural and religious beliefs keep people from donating their corneas.
Faced with a shortage, Griffith and her colleagues started working on artificial corneas 10 years ago in an Ottawa laboratory.
Griffith, a senior scientist at the Ottawa Hospital Research Institute and a professor at the University of Ottawa, later teamed up with Dr. Per Fagerholm, an eye surgeon at Linkoping University in Sweden.
They took collagen made in a lab and moulded it into the shape of a cornea.
“The end result is something that looks like a contact lens,” Griffith said.
After tests on pigs — whose corneas are about the same shape and size as ours — Griffith and Fagerholm operated on 10 Swedish patients in late 2007.
They took out the patients’ damaged corneas and stitched in the artificial, or biosynthetic, ones.
The researchers monitored the patients for more than two years. Slowly the cells and nerves grew into the implants. Their eyes did not reject the artificial corneas, a risk when using human donor tissue.
The new corneas became sensitive to touch and even started making tears to keep the eyes oxygenated.
Griffith and her colleagues in Sweden plan to use stronger and improved artificial corneas on more patients in the future.
Meanwhile, scientists at the Ottawa Hospital Research Institute and the University of Ottawa are trying to replicate Griffith’s work.
“A lot of the pre-clinical work was done here, and we’re moving in that direction,” said Dr. Duncan Stewart, head of the institute.
“So we’re hoping within the near future to be doing the first patient in North America here in Ottawa.”
Griffith says the artificial corneas could be used to patch torn or otherwise damaged corneas. The hope is to one day use them interchangeably with the real thing.
“Eventually, we hope that these corneas will supplement the donated corneas to help the short supply,” she said.