- Clinical trials using stem cells to treat dry macular degeneration shows promise.
- Stem cells are injected into the eye where they replace the damaged retinal cells.
- Stem cells are differentiated into retinal support cell, called retinal pigment epithelial (RPE) cells.
Results from two previous clinical trials show promise for the use of stem cells to treat dry macular
degeneration. Human embryonic stem cells were used to form retinal cells that
were injected into the eye. In one study the injected cells appeared to replace
the damaged cells with no side effects while in the other study the patient's vision
seemed to improve. The study was presented at the AAO 2017, the 121st Annual
Meeting of the American Academy of Ophthalmology.
Both clinical trials involved differentiation of embryonic stem cells
into a type of retinal support cells called retinal pigment epithelial (RPE)
cells. The RPE cells were then injected into patients with dry age-related macular degeneration
The first clinical trial was conducted by a research team from
Hadassah-Hebrew University Medical Center in Jerusalem, Israel. It was designed
to test the safety of injecting stem cells into human subjects. A suspension of
either 50,000 or 200,000 RPE cells derived from human embryonic stem cells was
injected underneath the patients' retina. Not only was the procedure well
tolerated, within weeks, the injection site on the retina was healed and the
transplanted RPE cells survived. The patient's vision remained stable and no
unexpected side effects were observed.
‘Injecting human embryonic stem cell derived retinal support cells replaces missing retinal pigment epithelial cells and improves vision.’
"RPE cells appear to be well tolerated in the human eyes," said
lead researcher Ninel Z. Gregori M.D., of Bascom Palmer Eye Institute.
"There were no serious adverse events attributable to the transplanted RPE
cells, including no tumor formation."
The second clinical trial was conducted by a research team from Bascom
Palmer Eye Institute in Miami. The study used RPE cells derived from human
embryonic stem cells to treat patients with dry AMD and also patients with a
different form of retinal degeneration called Stargardt disease. It's the most
common form of inherited juvenile AMD. The transplanted stem cells survived for
up to three years with no side effects. Some of these patients even reported to have improved vision.
"We're encouraged by the results thus far," said Eyal Banin,
M.D., Ph.D., lead investigator and one of the developers of the technology.
"But this is just a first step in the long road towards making
regenerative cell therapy a reality in macular and retinal degeneration
Dry Age-related Macular Degeneration
Dry AMD is the leading cause of new blindness in people over the age of
55. Thinning of the macula, which is responsible for clear vision in your
direct line of sight, causes blurred or reduced vision. It affects 30 million
people worldwide but there is currently no treatment for the disease.
Nutritional supplements do provide some form of protection from the retinal
degeneration. In a healthy retina, retinal pigment epithelial (RPE) cells
maintain nutrition and waste management of photoreceptors. When the RPE cells
are dysfunctional or damaged it results in vision loss
- Dry macular degeneration - (https://www.mayoclinic.org/diseases-conditions/dry-macular-degeneration/symptoms-causes/syc-20350375)