It
used to be an all day part of my life to
study on the latest goings on with research for RP.
Now,
about twice a year. Here are just a few
articals I have found today. Remember
not too long ago, there was nothing to
get that excited about online. Now?
Cells
taken from the donated eyes of dead people may be able to give sight to the
blind, researchers suggest. Tests in rats, reported in Stem Cells Translational
Medicine, showed the human cells could restore some vision to blind mice.
A
radical form of gene therapy that remodels eye cells into light receptors holds
out the promise of restoring sight to people who are completely blind. The new
approach is able to create replacement photoreceptors from cells that do not
normally react to light.
A
second electronic retinal implant trial will be starting soon, at the Oxford
Eye Hospital, run by Prof Robert MacLaren. Prof MacLaren and his team are
seeking RP patients to participate in this study.
The first clinical trial of a gene therapy for an
inherited cause of progressive blindness called choroideremia has shown very
promising initial results, surpassing the expectations of the researchers
involved. Professor Robert MacLaren of the Nuffield
Laboratory of Ophthalmology (part of the Nuffield Department of Clinical
Neurosciences) led the development of the retinal gene therapy and this first
clinical trial.
What is choroideremia?
Choroideremia is a rare inherited cause of
blindness that affects around 1 in 50,000 people. There is currently no cure.
It is caused by defects in the CHM gene on the X chromosome. Without the
protein produced by the CHM gene, pigment cells in the retina of the eye slowly
stop working, then die off. As the disease progresses, the surviving retina
gradually shrinks in size, reducing vision.
The aim of the treatment in this study was to get
the gene therapy into the cells in the retina of the eye without causing
damage. After six months, however, the patients actually showed improvements in
their vision in dim light and two of the six were able to read more lines on
the eye chart.
The gene therapy approach
The gene therapy approach developed by Professor
MacLaren’s team uses a small, safe virus to carry the missing CHM gene into the
light-sensing cells (photoreceptors) in the retina. In an operation
similar to cataract surgery, the patient’s retina is first detached and then
the virus is injected underneath using a very fine needle.
The aim is for the CHM gene, once delivered into
the cells of the retina, to start producing protein and stop the cells dying
off. The results suggest that the approach has promise for treating people
early on before too many cells in the retina have been lost. The approach also
has relevance for other, far more common causes of blindness where these
photoreceptors are affected, such as retinitis pigmentosa and age-related
macular degeneration.
Results
Results at six months are now reported for the
first six patients in The Lancet medical journal. Based on the success
of the treatment in the first six patients, three more have recently been
tested at a higher dose.
Professor MacLaren says: ‘It is still too early to
know if the gene therapy treatment will last indefinitely, but we can say that
the vision improvements have been maintained for as long as we have been
following up the patients, which is two years in one case. The results showing
improvement in vision in the first six patients confirm that the virus can
deliver its DNA payload without causing significant damage to the retina. This
has huge implications for anyone with a genetic retinal disease such as
age-related macular degeneration or retinitis pigmentosa, because it has for
the first time shown that gene therapy can be applied safely before the onset
of vision loss.’
“So
this one is not good for me as I’m too far down that track, but there is hope
above. Never give up on hope.
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