There is a new vision for a rare, hereditary disease.
Recent research has identified a unique treatment that could repair damaged retinas and even reverse vision loss.
This treatment, tested on an unexpected source, also suggests the possibility of repairing mammalian nerve cells, a feat once considered impossible.
Defective copies of the CaBP4 gene cause poor vision in childhood by creating a deficiency of a protein necessary for vision and signal transmission in the retina.
This protein can also affect dogs, leading researchers at the University of Michigan to create a potential cure by injecting animals’ retinas with a harmless virus carrying a working copy of the gene.
The single-dose treatment improved vision in dim light, where CaBP4 protein deficiency makes the most difference.
The treatment also helped damaged areas of the retina degrade less, while the outer plexiform layer that contains crucial connectors for vision and the synaptic ribbons inside the eye’s light-sensitive cells grew.
Growth of the outer plexiform layer and synaptic ribbons is delayed when the CaBP4 gene does not function properly. Researchers compared this underdevelopment to construction plans.
“One can essentially discuss retinal gene mutations as a typo in a plan that makes the instructions incomprehensible to the system, leading to faulty design and subsequent vision loss,” study leader Billie Beckwith-Cohen said in a press release.
The treatment allows the growth of a layer in the eye that has not formed as it usually would during retinal development, establishing that the outer plexiform layer of the retina has the capacity to change.
It also allows synaptic features that support good vision to develop properly, creating a better support system for the entire retinal neural network.
Another strength of single-dose treatment is its ability to reverse years of damage.
The team found that nerve cells were rewired even after years of stunted growth in the eye and resulting damage to nerve cell connections.
The benefits were also long-lasting, as evidenced by follow-up periods of three years after initial treatment.
Although this genetic disorder is rare in humans and dogs, the findings could provide other methods for repairing damaged neural networks.
Such an application would examine the role that calcium signaling plays in managing cellular communication in the eye – which also involves CaBP4.
The treatment has not yet been applied to humans. However, researchers are confident it will work.
“Our results show that gene therapy is not only capable of restoring retinal function, but also of establishing a near-normal anatomical arrangement in the retinal OPL,” they wrote in the article.
Gn Health
