Dormant in adults, stem cells have been found in the ciliary margin surrounding the lens. A team of Toronto scientists has uncovered the first evidence suggesting damaged eyes can heal themselves. The discovery could revolutionize the way doctors treat future eye injuries like those suffered by Bryan Berard, the Toronto Maple Leafs defenceman who was hit by a stick in the right eye last Saturday during a hockey game in Ottawa. Mr. Berard's known injuries include a detached retina, meaning the light-sensitive part of his eye is severed from delicate nerve tissue connecting it to the brain.
Retinal detachment is one of the most serious causes of lost vision.
At the moment, doctors can repair most cases by fusing the retina back in place using laser surgery or freezing techniques. Kooy's research team made the discovery in collaboration with Toronto's Hospital for Sick Children. Their work, published today in the U.S. journal Science, marks the first time scientists have found that even adult mammals have master cells, known as retinal stem cells, whose descendants are responsible for making every type of tissue in the eye. Until now, researchers believed only fish and amphibians had retinal stem cells capable of mending damaged eyes. It was also thought that these cells were found only in embryos or mammals in their early stages of development.