Picture of embryonic stem cells under the microscope
International Two groups of researchers have developed a new surgical technique for the treatment of cataracts with the use of stem cells. The experimental procedure was applied in 12 children with congenital cataract, causing them to recover vision.
Considered the leading cause of blindness in the world, cataract compromises the transparency of the lens - part of the eye that acts as a lens - making blurred vision. Currently, cataract surgery is the removal of the lens and its replacement by an intraocular artificial lens.
With the new technique, the scientists showed that it is possible to remove the cloudy lens preserving certain stem cells. This allows the cells to regenerate the lens, avoiding the installation of the artificial lens.
Both studies were published simultaneously on Wednesday, 9 in the journal Nature. In one, scientists demonstrated method with the successful regeneration of the lens, rabbits, monkeys and in 12 children with cataracts.
According to the authors, children treated with the new method - all with less than two years old - took a month to recover from surgery and had transparency increased eye 20 times, compared with children who underwent conventional surgery.
According to the study coordinator, Kang Zhang, of the University of California, San Diego (United States), the new method ensured better results and fewer post-operative complications in 12 children who participated in the study. "Crystalline regenerated extraordinarily well. We restore visual function and this implies that a transparent crystalline was regenerated," said Zhang.
One of the drawbacks of conventional surgery, according to Zhang, is that it requires a very large incision in the lens, which can lead to inflammation, delayed recovery and destruction of various epithelial stem cells, which play an important role in the crystalline damage protection external.
Zhang and his team succeeded in isolating epithelial stem cells in mammals, assess its regenerative capabilities and develop the method to preserve them during surgery. According to him, until now, the possibility of lens regeneration has not yet been demonstrated.
"Our method differs conceptually from current practices, to preserve the most of epithelial stem cells of the own body of the patient and their natural environment, regenerating crystalline with visual function. Our approach demonstrates a new strategy of treatment for cataracts and provides a new paradigm for tissue regeneration using stem cells, "says the article.
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In the other study, led by Kohji Nishida of the University of Osaka (Japan), the researchers were able to regenerate many different types of tissue in the human eye using stem cells in a manner that mimics the natural development of the eye itself. When transplanted into animals with resulting blindness compromised cornea, the tissues were able to recover the eye, restoring vision.
The eye is composed of several highly specialized tissues arising from a variety of cell lineages during development. Previous studies have shown that certain types of cells, such as those constituting the retina and the cornea, can be created in the laboratory from induced pluripotent stem cells - which are adult reprogrammed cells to acquire the capacity to give rise to any tissue. But these studies have not shown the complexity of the full development of the eye.
The staff Nishida eye could generate multiple cell lineages, including the cornea, lens and retina, using induced pluripotent stem cells. The researchers demonstrated that corneal epithelial cells can be grown and transplanted on the eyes of rabbits blind, in order to restore vision.
According to the authors, the work can open doors for future use in clinical human trials to transplant the front of the eye, leading to the restoration of visual function.
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