Scientists Make Remarkable Progress in Restoring Vision in Blindness Resulting From Photoreceptor Cell Degeneration

Researchers have developed an approach that involves the use of stem cells with the potential to correct vision problems and blindness.

Retina

The waning of photoreceptor cells, which are light-detecting cells, in the eye is a major cause of visual decline that may lead to blindness. It occurs in diverse inherited retinal diseases, including age-related macular degeneration (AMD) and retinitis pigmentosa.

There is no effective treatment for photoreceptor cell degeneration at this time.

The latest discovery, reported in the journal Molecular Therapy, was made by a team of scientists from Singapore and Sweden. These researchers observed notable vision recovery after transplanting progenitor photoreceptor cells from stem cells into experimental damaged retina models.

“Our laboratory has developed a novel method that enables the production of photoreceptor progenitor cells resembling those in human embryos,” stated the study’s first author Assistant Professor Tay Hwee Goon, who is from the Centre for Vision Research at the Duke-NUS Medical School. “Transplantation of these cells into experimental models has yielded partial restoration of the retinal function.”

This research signifies the first major step that could lead to the effective correction of eye conditions related to photoreceptor collapse.

Vision restoration with stem cells

The researchers in this study developed a method for growing embryonic stem cells from humans with input from purified laminin proteins, which play a role in the natural development of retinas in humans. With laminins present, stem cells could differentiate into progenitor photoreceptor cells that help to convert light into signals for transmission to the brain.

The experimental models used by the researchers displayed striking vision recovery after the transplantation of the progenitor cells into damaged retinas. Testing with an electroretinogram also revealed considerable recovery in retinas by way of electrical activity in response to a stimulus (light).

According to the researchers, the cells that were transplanted formed links to nearby retinal cells and nerves located in the inner retina. What’s more? The transplanted cells survived and worked for many weeks after being introduced.

Making progress

Senior study author Dr. Helder Andre, the head of Molecular and Cellular Research in the Department of Clinical Neuroscience at Sweden’s Karolinska Institute, expressed excitement at the results. According to him, the findings imply “a promising route towards using stem cells to treat those forms of visual deterioration and blindness caused by the loss of photoreceptors.”

Associate Professor Enrico Petretto, who led bioinformatics analysis in the study, noted that their new method may help know more about the molecular and cellular pathways involved in the progression of macular degeneration. The director of the Duke NUS’ Centre for Computational Biology said improved insight into this leading cause of vision loss could bring about “other therapeutic approaches.”

These researchers are now planning to hone their process to better simplify it.

They also want to make it more consistent, in terms of results. This will be in comparison to previous attempts to use stem cells for replacing damaged photoreceptor cells.

The team still has to surmount a major hurdle of proving the effectiveness of the method in photoreceptor degeneration models that tally with the human condition better. Clinical trials in patients will only come if researchers get promising results in future studies.