One-two punch could be key in treating blindness

András Komáromy and colleagues discovered that a combination therapy restored vision in dogs with an inherited retinal disorder. Credit: Photo by Tom Genarra

Researchers have discovered that using two kinds of therapy in tandem may be a knockout combo against inherited disorders that cause blindness. While their study focused on man's best friend, the treatment could help restore vision in people, too.

Published in the journal Molecular Therapy, the study builds on earlier work by Michigan State University veterinary ophthalmologist András Komáromy and colleagues. In 2010, they restored day vision in dogs suffering from achromatopsia, an inherited form of total , by replacing the associated with the condition.

While that treatment was effective for most younger dogs, it didn't work for canines older than 1 year. Komáromy began to wonder if the older dogs' cones – the in the retina that process daylight and color – might be too worn out.

" only works if the nonfunctional cell that is primarily affected by the disease is not too degenerated," he said. "That's how we came up with the idea for this new study. How about if we selectively destroy the light-sensitive part of the cones and let it grow back before performing gene therapy? Then you'd have a younger, less degenerated cell that may be more responsive to therapy."

So, Komáromy and colleagues recruited more dogs with achromatopsia between 1 and 3 years old. To test their theory, they again performed gene therapy but first gave some of the dogs a dose of a protein called CNTF, which the produces to keep cells healthy. At a high enough dose, its effect on is a bit like pruning flowers: It partially destroys them, but allows for new growth.

"It was a long shot," said Komáromy, associate professor in MSU's Department of Small Animal .

But it worked.

"We were just amazed at what we found," he said. "All seven dogs that got the combination treatment responded, regardless of age."

While achromatopsia is quite rare, Komáromy said it's a good model disease for other disorders affecting the photoreceptors, conditions that constitute a major cause of incurable blindness in dogs and humans. Those disorders affect individuals of both species in much the same way, so the combination treatment's promise isn't just for Fido.

"Based on our results we are proposing a new concept of retinal therapy," he said. "One treatment option alone might not be enough to reverse vision loss, but a combination therapy can maximize therapeutic success."

Related Stories

New twist in a blindness-causing disease gene found

date Sep 21, 2011

After more than three decades of research, University of Pennsylvania veterinarians and vision-research scientists, with associates at Cornell University, have identified a gene responsible for a blindness-inducing disease ...

First clinical trial of gene therapy for childhood blindness

date May 01, 2007

The first clinical trial to test a revolutionary treatment for blindness in children has been announced by researchers at UCL (University College London). The trial, funded by the Department of Health, is the first of its ...

Recommended for you

Lowering risk of a major eye disease

date May 20, 2015

Age-related macular degeneration (AMD), a chronic, progressive disease, is a leading cause of blindness among people aged 65 and older. Vision impairment due to advanced AMD significantly reduces quality ...

Age-related macular degeneration, mortality linked

date May 12, 2015

(HealthDay)—Age-related macular degeneration (AMD) is a predictor of poor survival, especially among women aged 80 years and older, according to a study published online May 4 in the Journal of the American Ge ...

Short-sightedness becoming more common across Europe

date May 11, 2015

Myopia or short-sightedness is becoming more common across Europe, according to a new study led by King's College London. The meta-analysis of findings from 15 studies by the European Eye Epidemiology Consortium ...

Smart microchips may optimise human vision

date May 11, 2015

To date, chip-based retinal implants have only permitted a rudimentary restoration of vision. However, modifying the electrical signals emitted by the implants could change that. This is the conclusion of ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.