Colorblindness cure in monkeys promising for human cure

In 2009, two red-green color-blind squirrel monkeys saw a new spectrum of colors. And in the next decade or two, colorblind humans might as well.

Dr. Jay Neitz, bishop professor in the UW Department of Ophthalmology, and a team of researchers are expanding research in colorblindness and other vision disorders at the UW.

“The whole reason that we wanted to attempt to cure colorblindness in the monkeys is as a way to develop a general method for treating eye disorders using gene therapy,”

Neitz said. “Before we did those experiments, it was just an idea that you might be able to cure disorders of the eye in people with gene therapy.”

Neitz said these findings show that it is feasible to cure colorblindness in humans as well as other types of blinding eye disorders that are currently untreatable.

“The purpose for doing these experiments is not to cure colorblindness in monkeys; it’s to cure colorblindness in people,” said Scott Greenwald, a graduate student in the UW neurobiology and behavior program. “That is truly what we are interested in.”

Greenwald has been researching the genetic mutations involved in colorblindness with mouse models, which have the same dysfunctional gene as people. He’s working to cure this by finding how to best administer gene therapy in humans.

“In order to be able to try this in humans, you have to prove that treatment is both safe and effective,” Neitz said. “We think that the experiments in squirrel monkeys go a long way in providing the kind of evidence that we would have to show that it is effective.”

But, Neitz said, using humans as participants would require far more safety-protocol requirements, which is what the team of researchers is currently working on perfecting. In the United States, one in 12 men and one in 230 women have red-green colorblindness, the most common single genetic disorder in human beings.

Neitz said a problem that many color-blind people have is found in the workplace, where people sometimes need color vision to look at color-enhanced images.

Recently, researchers began studying how to administer the therapy. The monkeys were administered the gene therapy behind their retinas inside of their eyes, and Neitz said making the medicine administrable through a small shot to the eye would be more streamlined for human treatment to reduce the risk of other complications.

Candice Davidoff, a graduate student in neurobiology and behavior, has been studying the diagnostics of colorblindness and links of the cone opsin gene, which causes colorblindness, with other vision disorders. She has developed a genetic screen with a company called Genevolve for detecting color-vision defects that will be commercially available in the near future.

Neitz and UW researchers have ongoing studies for people with vision disorders and are currently recruiting volunteers.

Reach contributing writer Genevieve Huard at development@dailyuw.com. Twitter: @GenevieveDahl

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