NRL News

Embryonic Stem Cells Injected Into Eyes

by | Jul 15, 2011

By David Prentice

Cloning company Advanced Cell Technology (ACT) has announced that two human patients have been injected into their eyes with embryonic stem cell derivatives.  The two are the first one, each, in two different experiments related to two eye diseases, Stargardt’s macular dystrophy and age related macular degeneration. 

According to a press release from ACT both people received only a few thousand cells made from embryonic stem cells. Supposedly a total of 12 patients each will be injected with increasing doses of embryonic stem cells over the next two years, but few other details are available.  These experiments with human patients are designed to test the safety of these cells, but it is unknown how long the patients will be monitored for problems.  Why is that important?

What proponents rave about—that these cells proliferate—has a dark side (beyond  the grim fact that embryonic stem cell research relies on the destruction of young human life): a significant tendency to form tumors.  Indeed, research shows that tumor formation can occur starting with as few as two growing embryonic stem cells, and it is extremely difficult to remove every growing cell from a group of cells.  The fact that neither ACT nor Geron (the other group injected embryonic stem cells into patients) has proven that they can control tumor formation is a significant concern, even among proponents of embryonic stem cells.

ACT was not the first to inject embryonic stem cell derivatives into patients.  Geron has injected a total of two spinal cord injury patients with embryonic stem cell derivatives in the last few months.) Notably, Geron has said that the company will follow patients injected with embryonic stem cells for 15 years, primarily due to the tumor risks from the embryonic stem cells.  (See

In a story about ACT’s test in this morning’s Washington Post, there was this quiet reminder that even supporters have qualms: “And some proponents worry about whether the approach is safe and has been adequately vetted before being tried in people.”

Embryonic stem cells unethically risk the lives of patients.

By contrast, ethical and successful adult stem cells are treating thousands of patients every year, including for some types of blindness.  A year ago, Italian scientists published results showing recovery of sight in over 77% of blind patients treated with their own adult stem cells, including one man who had been blind for 50 years.  Check out some of the other stories at

Dr. Prentice is Senior Fellow for Life Sciences, Family Research Council