Stem cell therapy against old-age blindness AMD

New hope for AMD patients

16/10/2014

Thanks to a new stem cell therapy, the vast majority of AMD patients treated in this way can see much better again, according to Spiegel Online, citing the specialist magazine „The Lancet“. So far, there was no recognized method for treating the incurable old-age disease. Most of those treated suffered from age-related macular degeneration (AMD). It is the most common cause of blindness in patients over the age of 50. The disease causes the cells of the retina to lose their function and patients to see more and more blurred until they can only perceive shadows and are considered medically blind.

Now there is hope for an effective therapy. The basis of the therapy are embryonic stem cells, which the US researchers led by Steven Schwartz from the University of California in Los Angeles got from a one-day-old embryo from a fertility clinic. The special thing about these cells is that they are universal, and any kind of cells, e.g. Skin tissue, heart muscles or even cells for the eye can emerge from them.

In the present case „programmed“ According to Spiegel Online, the researchers created the cells in such a way that they produced the cells of the retinal pigment epithelium that had been destroyed in AMD patients. The genetic material of the stem cells was manipulated by chemicals and grown until they had the desired state and then transplanted 18 patients in each eye. Of these, nine suffered from AMD and nine from so-called Stargardt's disease, a very rare form of macular degeneration that occurs in childhood and adolescence.

Vision significantly improved
The experimental therapy lasted over two years and was successful in all patients treated. This is confirmed by eye tests with the test persons. Patients were able to read with the treated eyes while the condition of the untreated ones worsened, reports Schwartz. A farmer could ride again and other patients could use computers again, read clocks or orient themselves independently in everyday life, according to Robert Lanza of the company Advanced Cell Technology, the company that financed the study and produced the stem cells. „This is a promising study and it offers a lot of hope for regenerative medicine, "said Dr. Steven Schwartz, opposite the online edition of „The New York Times“. „But there is a lot of work to do. "

First long-term study on the use of embryonic stem cells in humans
The study is also unique because it is the first long-term study on the use of human embryonic stem cells. And she has proven, according to Lanza, that the use of the cells, contrary to the previously existing opinion that they could degenerate and form tumors, longer term safe and functional.

Spiegel Online reports that the procedure was first applied to two AMD patients in 2011 and was intended to test the general tolerability of stem cells. An improvement in vision was noted even then. At the time, however, no forecasts were possible about longer-term security. Partly because of this, and because the study was only conducted over a 4-month period and, as mentioned above, there were only two subjects, Schwartz and Lanza were criticized by their colleagues for the early optimism expressed in their study, according to New York Times on. This longer-term security has now proven the recent study, as reported by Spiegel Online. However, there were already side effects: in four cases, a cataract developed and two lenses became inflamed. The researchers are responsible for the high age of the patients and the immune rejection preventing the tissue rejection.

Ethical reservation therapy still in the experimental stage
However, it will take some time until the therapy becomes generally available, although the therapy is promising according to Dusko Ilic of Kings College London. In addition, the ethical debate about the extraction of stem cells, ie the killing of embryos, is by no means over, especially as there are now alternatives to this. Thus, for example, from body cells produce cells similar to those of embryonic stem cells.

First tests with these so-called IPS cells already existed in 2014. The aim was to test the tolerability, because these cells are even more suspected, they could mutate and form tumors. Incidentally, the subject could not see better, according to Spiegel Online. (Jp)