YOUR HEALTH: Something fishy to help improve eyesight

Macular degeneration is the leading cause of vision loss for adults over the age of 60

NASHVILLE, Tenn — Age-related loss of eyesight affects 11 million people in the United States and that number is expected to nearly double by 2050. 

But tiny zebrafish may help improve that outlook.

ish might be tiny, but they come with some supersized powers.

"Zebrafish, unlike mammals, are able to regenerate parts of their retina if they become injured," explained David Calkins, director of the Vanderbilt University Vision Research Center.

Researchers from Vanderbilt University Medical Center are studying how this characteristic of zebrafish can help humans dealing with age-related vision loss due to damage to the retina.

"The cells that make up the retina between the fish and the human eye are very, very similar," said James Patton, a Vanderbilt Biological Sciences professor.

Except for one cell called MG for Muller Glia

In a zebrafish, when that cell is damaged it will activate and then regenerate.

"So the fish will go from blind to about two-and-a-half weeks later, total regain of eyesight," Patton added.

The zebrafish is used often to study human traits and diseases because they share 70% humans' genetic code.

Humans have the same Muller Glia cell but are incapable of regeneration like the zebrafish. 

But Patton said he is trying to find out if suppressing a certain type of micro-RNA in humans could activate Muller Glia the same way it does in zebrafish.

There is a treatment where stem cells are injected into the back of the eye to see if those stem cells will integrate into the retina and then replace lost cell types. 

A stem cell that's already a resident cell in the retina is used to replace all the rest of the lost cells 

This is similar to the method that the Muller Glia cell naturally does in the zebrafish.  

Right now, the economic burden for eye disorders and vision loss sits at $35 billion. 

"If there were ways to keep people seeing and overcome degenerative disorders, that would have a huge economic impact, not to mention quality of life," said Patton.

Before human testing, they will have to test on smaller mammals, such as mice and see if they can suppress a particular mirco-RNA that regulates the Muller Glia cell.

If this story has impacted your life or prompted you or someone you know to seek or change treatments, please let us know by contacting Jim Mertens at jim.mertens@wqad.com or Marjorie Bekaert Thomas at mthomas@ivanhoe.com.