gator Posted November 10, 2006 Share Posted November 10, 2006 LONDON: British scientists have restored vision to blind mice in a breakthrough that raises hopes for thousands of people affected by the most common causes of blindness. Doctors at Moorfields Eye Hospital and the Institute of Child Health in London repaired the animals' eyes in the world's first successful transplantation of light-sensitive cells into retinas. The treatment replaces photoreceptor cells killed off by retinitis pigmentosa, an incurable condition that afflicts one in 3,500 people, and macular degeneration, the most common cause of blindness, which affects up to 15 per cent of people over 75. The success follows a series of failed attempts to cure blindness by transplanting stem cells and adult retinal cells, neither of which formed the right nerve connections to pass signals from eye to brain. In the latest research, reported in Nature on Thursday, Jane Sowden and Robin Ali injected precursors of light-sensitive cells taken from three- to five-day-old mice into the eyes of adult mice bred to have a genetic defect that causes blindness. Of about half a million cells transplanted into each eye, between 300 and 1,000 formed nerve connections. The mice showed signs that their vision was recovering. Their pupils responded normally to bright lights by shrinking and electrical activity in the retina showed the transplanted cells were passing signals on to the optic nerve. The successful animal studies pave the way for trials in humans, although the scientists warn a treatment might be at least 10 years away. In the experiments the transplanted cells were taken from newborn mice that were genetically matched to the blind animals to minimise the risk of immune rejection. In humans similar precursor cells are believed to grow around the iris. This raises the possibility that blind people might be cured by having injections of cells collected from their own eyes. ? http://www.hindu.com/2006/11/10/stories/2006111000582200.htm Link to comment Share on other sites More sharing options...
gator Posted November 10, 2006 Author Share Posted November 10, 2006 Re: Terrific new: Blindness can be cured... hope this works out sooner than the 10 years.... Link to comment Share on other sites More sharing options...
gator Posted November 10, 2006 Author Share Posted November 10, 2006 Re: Terrific new: Blindness can be cured... doc, whats ur take on this??? Link to comment Share on other sites More sharing options...
Dhondy Posted November 10, 2006 Share Posted November 10, 2006 Re: Terrific new: Blindness can be cured... Will post in detail later today, gator. Link to comment Share on other sites More sharing options...
King Posted November 10, 2006 Share Posted November 10, 2006 Re: Terrific new: Blindness can be cured... That is an excellent development. I just hope the method of curing blindness is affordable so that the poor ones can take advantage of this. Link to comment Share on other sites More sharing options...
Dhondy Posted November 10, 2006 Share Posted November 10, 2006 Re: Terrific new: Blindness can be cured... Gator, we see a lot of false dawns like these. It would be nice to have a cure for Retinitis pigmentosa, in particular, which affects young people. However, animal experiments don't always translate well into humans. For example, finding genetically matched dead human embryos for the blind recepients would be horrendously difficult, and has huge ethical & logistic implications. Even if I were to assume that precursor cells could be obtained from the anterior chamber of the eye, the ambiguity of the following statement gives very little hope that it would be one day possible, "In humans similar precursor cells are believed to grow around the iris." Believed? So we don't even know yet! Cells obtained from different compartments of the eye do not necessarily rule out an immune rejection. In sympathetic ophthalmia, for example, an injury to the eye triggers off an immune reaction to its own components, which had been sequestered from the immune "sentinels" during embryonic development. If autologous cells cannot be obtained, what about immunosuppression? Will the frail, elderly with senile macular degeneration need highly toxic cytotoxic drugs to prevent rejection, as kidney allograft recepients do? Ten years may be an underestimate. Link to comment Share on other sites More sharing options...
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