Posted on Feb 03, 2012, 6 a.m.
UCLA-led team safely uses human embryonic stem cells to treat macular degeneration.
In the first-ever application of its kind, University of California/Los Angeles (UCLA; California, USA) scientists safely use human embryonic stem cells to treat macular degeneration in two patients. Steven Schwartz and colleagues also reports that some evidence suggested improvement in vision in this pilot study of patients with severe vision loss and two different forms of the disease (dry age-related macular degeneration, and a case of Stargardt's macular dystrophy). The team conducted a controlled differentiation of the cells that resulted in a culture of retinal pigment epithelium cells that was 99% pure and, in animals, injection of the retinal cells was not associated with tumor formation or with any other safety issues. The researchers injected 50,000 retinal pigment epithelium cells through a fine cannula into the subretinal space of one eye in each of the two patients and followed them for four months. Both patients each ch had low-dose immunosuppression therapy starting a week before the procedure and continuing for six weeks afterward. Whereas Both patients were legally blind prior to the procedure the researchers reported that he patient with macular degeneration improved from 21 letters on the Early Treatment Diabetic Retinopathy Study visual acuity chart to 33 letters at week two, stabilizing at 28 though the rest of the study period. The patient with Stargardt's disease had clear improvements, and went from being unable to see hand movements at all to being able to see single finger movements. On the diabetic retinopathy acuity chart, she went from being able to read no letters to five. Reporting that: [the stem-cell derived retinal pigment epithelium cells “showed no signs of hyperproliferation, tumorigenicity, ectopic tissue formation, or apparent rejection after 4 months,” the study authors urge that: “The future therapeutic goal will be to treat patients earlier in the disease processes, potentially increasing the likelihood of photoreceptor and central visual rescue.”
Steven D Schwartz, Jean-Pierre Hubschman, Gad Heilwell, Valentina Franco-Cardenas, Carolyn K Pan, Robert Lanza, et al. “Embryonic stem cell trials for macular degeneration: a preliminary report.” Lancet, 23 January 2012.