Two patients who received retinal stem cell implants show potential signs of improved vision – despite having an incurable eye disease.
US firm Advanced Cell Technology told The Lancet that structural evidence confirmed the cells had attached to the eye’s membrane as hoped, and continued to survive throughout the next 16 weeks of the study, with no signs of rejection or abnormal cell growth.
The operation involved implanting embryonic stem cells into the damaged retina at the back of the eye. The controversial transplants of embryonic cells is part of an ambitious attempt to utilise stem cells. Stem cells have the ability to develop into any specialised tissue of the body. Such procedures face criticism from those who belief the use of human embryonic tissue to be unethical.
Dr Dusko Ilic, Senior Lecturer in Stem Cell Science at Kings College London, said that these early findings did not necessarily hint towards a viable treatment, saying: “we should keep in mind that people are not rats.
“The number one priority of initial clinical trial is always patient safety. If everyone expects that the blind patients will see after being treated with human embryonic stem cell-derived retinal pigment epithelium, even if the treatment ends up being safe (which is what Advanced Cell Technology are trying to determine in this trial), they risk being unnecessarily disappointed.”
It is too early to make conclusions yet, though it appears as if the procedure is safe.
UK stem cell expert Chris Mason said: “We do not have a complete answer yet. But it is a valuable next step.”
- Embryonic Stem Cells Appear Safe, May Help Eye Disease (news.sciencemag.org)