JUL 12, 2021 9:59 AM PDT

Vision of Retinitis Pigmentosa Patient Partially Restored by New Therapy

WRITTEN BY: Carmen Leitch

Scientists have been developing gene therapies that can help restore vision that's lost due to a problem with a gene, and one kind of gene therapy might be able to help people that have vision problems regardless of what gene has caused the problem. Researchers have now demonstrated that optogenetic therapy has the potential to help people with a genetic disorder called retinitis pigmentosa, in which rod and cone cells die off.

Image credit: Max Pixel

Reporting in Nature Medicine, scientists treated a 58-year-old retinitis pigmentosa patient with optogenetic therapy. After the therapy, he regained the limited use of his vision if he used special goggles that delivered amber light pulses to his dysfunctional eye, which had received the treatment.

In previous iterations of this therapy, a protein called channelrhodopsin-2 was isolated from algae and delivered to patients. But in order for the protein to work, a lot of blue light stimulation was needed - so much light that it was potentially harming other cells. Researchers set out to find a different method, and they created a technique that sends the genetic instructions to make the protein to ganglion cells in the eye instead; the genetic material is contained in a vector called an adeno-associated virus (AAV).

After light is collected by rod and cone cells, the information is sent on to bipolar cells and then ganglion cells, which send the visual information to the brain. The ganglion cells are also easy to reach to deliver the treatment; the AAV can simply be injected into the center of the eye. The ganglion cells remain even when rods and cones die.  

Optogenetic proteins only work within a range of conditions, however, and aren't a substitute for normal vision. When a light source is constant, these ganglion cells won't keep firing on their own. As such, the patient has to wear goggles that deliver light pulses to his eye. Any patients getting this therapy in the future may also need special goggles.

But, the man can now see and count objects even though he could not before; he can pick out objects on a table, the stripes in a crosswalk, and detect motion. While this is not a cure for blindness, it could be a huge improvement for many people.

Preliminary results from a company called Bionic Sight that's also trying to create ontogenetic therapies have been successful, they reported. Specific information about those results have not yet been released, however, and cannot be evaluated.

Sources: Science News, Nature Medicine

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAY 11, 2021
Cell & Molecular Biology
Problems in Human Egg Fertilization Are Common
MAY 11, 2021
Problems in Human Egg Fertilization Are Common
This ©MPI for Biophysical Chemistry microscopy image shows a bovine egg after fertilization.
JUN 08, 2021
Genetics & Genomics
Primers and Probes to Assay for SARS-CoV-2 Variants in Research Samples
JUN 08, 2021
Primers and Probes to Assay for SARS-CoV-2 Variants in Research Samples
Today, many scientists are investigating SARS-CoV-2 variants in their research projects. In order to facilitate screenin ...
MAY 27, 2021
Neuroscience
Research Less Likely to Be True is Cited More
MAY 27, 2021
Research Less Likely to Be True is Cited More
Researchers from the University of California San Diego have found that non-replicable data is cited 153 times more ofte ...
JUN 25, 2021
Genetics & Genomics
Towards More Efficient Plant Engineering with CRISPR-Cas9 Gene Drive
JUN 25, 2021
Towards More Efficient Plant Engineering with CRISPR-Cas9 Gene Drive
Many people in the world don't have access to enough food. And while humans might find ways to adapt to a changing world ...
JUL 04, 2021
Genetics & Genomics
New Insights Into the Mechanisms of Rett Syndrome
JUL 04, 2021
New Insights Into the Mechanisms of Rett Syndrome
Rett syndrome is a neurological disorder that mostly affects girls; affected individuals develop normally until they're ...
JUL 18, 2021
Genetics & Genomics
Only 7% of the Human Genome or Less is Unique to Modern Humans
JUL 18, 2021
Only 7% of the Human Genome or Less is Unique to Modern Humans
Genetic tools have enabled scientists to assess the evolution of humans through DNA, and researchers have shown that mod ...
Loading Comments...