Restoring Lost Sight May Become a Reality

v>In addition to growing the cells in the lab and
The ability of zebrafish to regenerate damagedtransplanting them back into the eye, the
retinas has given science a clue about restoringresearchers are looking at ways to stimulate
human vision.  This could lead to a treatment forgrowth and influence the eye to repair itself using
blindness within five years.its own cells. Using one’s own cells rather
Zebra fish may open up an opportunity inthan a donor’s has the advantage that the
preventing, or reversing blindness. A special typeimmune system is less likely to reject the
of cell found in the eye of zebra fish has beentreatment. Although Muller glial cells are present in
found to be very important in regenerating thethe human eye, it is not clear why they do not
retina, and restoring vision even after extensiveautomatically repair the retina. It is possible that
damage. These stem cells are called Muller glialinternal mechanisms exist in the normal adult
cells, and scientists believe they may be able toretina that prevents these cells from dividing and
use these cells to regenerate damaged retinas inreplicating. The next step is to identify which
humans. The retina is the part of the eye thatfactors are responsible for blocking the
receives light, and transmits images to the brain.regeneration.
When damaged through Glaucoma, MacularResearchers hope that this research may lead to
Degeneration and Diabetic Retinopathy to name aa treatment within five to ten years, for cells
few, the individual loses their vision permanently.isolated from a person’s own eye.
Just why zebra fish have an abundance of theseHowever, the need to overcome the immune
adult stem cells to regenerate their retinas, whileresponse for transplantation of a donor’s
they are very rare in humans remains a mystery.cells means that this second approach would take
British researchers have successfully grown in thelonger. In any case, a treatment for diseases such
lab this type of adult stem cell that develops intoas macular degeneration, glaucoma and
neurons in the retina. These cells could be injecteddiabetes-related blindness seems to be right
into the eye as a treatment for retina damagingaround the corner. Dr Astrid Limb, who led the
diseases. When tested in rats with diseasedstudy states. ‘Our findings have enormous
retinas, the cells migrated into the retina and tookpotential.’ ‘It may be possible to store
on the characteristics of the surrounding neurons.the cells in a cell bank and transplant them into
Researchers are now looking at developing thisthe eye or to use cells from a person’s
approach for use in the human eye.own eye.’ .