Stem Cell Therapy to Treat Dry Macular Degeneration

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.

Clinical trial

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 (AMD). 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.

"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.

References:

1. Dry macular degeneration - (https://www.mayoclinic.org/diseases-conditions/dry-macular-degeneration/symptoms-causes/syc-20350375)

Source-Medindia