Compared to the questionable success of embryonic stem cells, adult stem cells have been achieving some real successes in retinal repair studies, without the complication issues of tumors, etc. and without the ethical problems associated with embryonic stem cells.

A couple of examples of recently published studies.

In a paper published February 15, 2010, Oregon scientists showed that they could use bone marrow-derived adult stem cells to treat a rat model of retinitis pigmentosa. Visual function was significantly preserved in this study. An added benefit was that the cells could be easily grown in culture and administered intravenously; once injected, they traveled to the retina where they exerted their protective effect. The study highlights the possibility of using a patient's own adult stem cells for treatment of retinitis, diabetic retinopathy, and macular degeneration.

A study by Canadian and Japanese researchers used human retinal stem cells that had been modified to increase their differentiation potential. When injected into the eyes of mice, the adult stem cells survived and differentiated into photoreceptors. Injected into a mutant mouse strain that lacks functional photoreceptors, the adult stem cells significantly improved visual function. The study was published online in the journal Stem Cells December 11, 2009.

In Louisville, they are close to initiating a clinical trial using adult stem cells for treatment of macular degeneration.

Looking at a different part of the eye, adult stem cells have already been used successfully in patients to treat corneal blindness.

There are other examples of real adult stem cell successes for visual repair if we want to go back further. And unlike "potential" embryonic stem cell experiments which rely on sacrificing some human beings, adult stem cell research doesn't require destroying the cell donor, instead often using the patient's own adult stem cells for the treatment. Real success and real science.