Promising results in the search for a cure for blindness affecting millions of people appeared this week in the nation’s oldest medical journal, The Lancet.
Doctors in California released early findings from their treatment with human embryonic stem cells for a patient suffering from Dry Age-Related Macular Degeneration — “Dry AMD,” the most common cause of blindness among the elderly. Ten million Americans have been diagnosed with the disease. There is no known cure.
Stem Cell Researchers
Human Embryonic Stem Cells were transplanted last summer into the retinas of a 77-year-old woman whose deteriorating vision had left her legally blind. Four months into treatment, her vision has improved significantly.
Dry AMD is said to be the developed world’s leading cause of blindness. According to statistics, it is the leading cause of blindness in people over the age of 55. Diagnoses are expected to double in the near future as the number of elderly Americans grows.
Dr. Olaf Strauss, who heads Experimental Ophthalmology at Regensburg University Medical Center in Germany, has been studying Macular Degeneration for decades. “Basically the disease AMD starts in the retinal pigment epithelium,” he said in an email. “A loss of RPE cells is an entry mechanism to AMD. Thus the strategy to replace cells is just right. It seems that transplantation does not harm the remaining vision and the cells survive and might show some differentiation.”
This is the first time scientists have transplanted retinal pigment epithelial cells derived from human embryonic stem cells into human patients. The clinical trial was conducted at UCLA’s Jules Stein Eye Institute.
“We can be happy about this first successful step,” Dr. Strauss said.
No one knows what causes Dry Age-Related Macular Degeneration. But people diagnosed with the disease face increasing loss of sight. Because there is no way to slow or halt the progression of the disease, the outlook can be devastating.
Actress Judi Dench revealed earlier this month she is suffering from the disease, which affects the delicate, single-celled macular tissue over the retina and progresses slowly and steadily.
Biotech breakthrough
The transplant technique was conceived and funded by Advanced Cell Technology, a Santa Monica, California, biotech firm which holds patents on several techniques involved in the treatment. ACT is the only company the FDA currently allows to use embryonic stem cells in its clinical trials.
An ACT press release announcing the encouraging results included a statement from Gary Rabin, chairman and CEO: “The data underscore the potential of stem cell therapies and regenerative medicine to realize the possibility repairing or replacing tissues damaged from disease,” implying that the new data may lead to treatments for other eye diseases — not just Dry AMD. Rabin said his company will “take advantage of our patented techniques for manufacturing large numbers of doses of RPE cells.”
Back in Germany, Dr. Strauss is not ready to call this treatment a “cure” for Macular Degeneration — yet.
“One should be very patient and careful with studies of that kind,” he said. “There have been studies in the past which have closed the doors for new therapeutic approaches because they were not successful. We have to wait for a next step.”
ACT’s program treated two human patients, both legally blind.
One had been diagnosed with Dry Age-Related Macular Degeneration. The other had Stargardt’s Disease, a similar type of blindness found in children. Trials now proceed with two dozen patients diagnosed with Macular Degeneration.