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Dr. Liz James, Head of Research at the Blond-McIndoe Centre, has worked to provide ophthalmic surgeons at the Corneoplastic Unit with sheets of corneal epithelial stem cells to graft onto the patient's cornea, in order to stabilize and protect the cornea surface with new cells. Often, the source of cells is a small biopsy the size of a pin-head from the patients other eye, providing this is healthy and not damaged. In other cases, the stem cell donor tissue may come from a close relative or from eyes donated to the Queen Victoria Hospital Eye Bank. In all cases, presumed stem cells from the small tissue sample are grown in culture and then grafted onto the eye of the patient.
In collaboration with Mr Sheraz Daya, Queen Victoria Hospital (Director of the Corneoplastic Unit and Centre for Sight), several patients have been treated using grafts of these cultured cells. The patients had severe deficiencies for many years, and other conventional treatments had failed. The first three patients were grafted more than 5 years ago, and after their corneal surfaces had stabilized using this new technique they were given a cornea graft in the centre of the eye to restore their vision. Importantly, these patients did not show any detrimental effects of the treatment.
The treatment has now been extended and stem cell transplants are offered to patients with serious corneal surface disease.
One biological question we have tried to answer is whether the cultured donor cells have survived sufficiently long to be able to stimulate the regeneration of the patient's own tissue. Using forensic DNA fingerprinting techniques, Justin Sharpe has been able to show that donor cells can be demonstrated on the cornea over the first 3 to 4 months, and that the good epithelial recoveries we have observed over the longer term seem due to the patient's own cells. This we believe is a breakthrough and has considerable future implications. At a minimum, the need for long term immunosuppression following surgery may not be necessary. Additionally extrapolating on our work, there is the potential to regenerate other forms of tissue from the body's own stem cells. Much work needs to be conducted and presently without funding and resources is beyond our scope at the Queen Victoria Hospital.
This work on stem cell transplantation to reconstruct the ocular surface has been presented nationally and internationally at the American Academy of Ophthalmology meeting (2003) and published in peer reviewed literature (Ophthalmology 2005 Mar;112(3):470-7 Outcomes surface reconstruction and DNA analysis of ex vivo expanded stem cell allograft for ocular surface reconstruction).
For more information on basic science research at the Queen Victoria Hospital
please click here: www.blondmcindoe.com
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