On the use of "stem cells" for optic nerve hypoplasia.

R In the past few years, the medical community has seen an explosion of knowledge and has felt cautious optimism about the future use of cell-based therapies for numerous diseases—including blinding diseases of children. In general, these potential therapies are centered around stem cells, which can be divided into 3 categories: (1) pluripotent embryonic stem (ES) cells derived from human embryos; (2) induced pluripotent stem cells, in which differentiated cells, such as skin fibroblasts, are “reprogrammed” to “dedifferentiate;” and (3) somatic stem cells (SSC), derived from tissues such as umbilical cord blood and bone marrow. With the exception of limbal stem cell transplantation in corneal opacification, the use of various forms of stem cells, for the treatment of eye disease, has only been studied systematically in animal models. Recently, novel treatments using cell-based techniques have been advocated for patients with otherwise untreatable congenital ocular malformations such as optic nerve hypoplasia. An example is a website from China. According to the websites of those offering these regimens, children who undergo infusion of somatic stem cells, such as those derived from umbilical cord blood—often along with adjunctive therapy, such as acupuncture and physical therapy–are reported to have improvements in their visual behavior. Most often, these procedures are performed in countries where government oversight of medical consumer safety is limited. The practice of marketing cell-based therapies for optic nerve hypoplasia concerns us for several reasons. First, we are concerned about its safety and efficacy. The use of biologic material in the treatment of human disease in the absence of regulated quality control of reagents places patients at risk for adverse events. Possible adverse events may include untoward immune reactions and transmission of infectious agents. A PubMed search of “optic nerve hypoplasia” and “stem cells” reveals no peerreviewed articles supporting safety or efficacy— even in principle— of this technique. The information provided on websites for such therapies typically relies on anecdotes and patient/family testimonials. Because visual function assessment in young children is particularly susceptible to effort, learning, mood, suggestion, and the placebo effect, the visual function data provided by the advocates of these cell-based therapies are currently insufficient to justify patient treatment. Second, these cell-based therapies target a vulnerable population (children) who are unable to legally provide