I came across this really interesting press release from the University of Pennsylvania that I just had to share.
Despite having a close relationship with dogs for thousands of years, we are still making new discoveries about our canine friends. Drs. William Beltran (School of Veterinary Medicine), Artur Cideciyan (Perelman School of Medicine), and colleagues teamed up to study canine eyes in an effort to improve treatments for humans with retinal diseases.
Dr. Beltran was quoted as saying “It’s incredible that in 2014 we can still make an anatomical discovery in a species that we’ve been looking at for the past 20,000 years, and that, in addition, this has high clinical relevance to humans.”
Prior to their research it was assumed that, unlike primates, dogs do not have a fovea (the pit in the middle of the retina that contains numerous cone photoreceptor cells). The new research published in PLoS ONE, used advanced imaging to show that dog eyes do have a tiny region packed with greater than 120,000 cone photoreceptor cells per square millimeter in the center of their retina. This density is much higher than previously reported for dogs and is similar to the fovea of primates.
The researchers also explored genetic mutations that are associated with macular degeneration in humans. Macular degeneration is a leading cause of blindness over age 65y and results in a loss of central vision (see image below). They found that dogs with similar mutations in these genes also had similar anomalies in the fovea-like region of the retina.
Dr. Cideciyan was quoted as saying, “Our findings, which show the canine equivalent of a human genetic disease affecting an area of the retina that is of extreme importance to human vision, are very promising from the human point-of-view. They could allow for translational research by allowing us to test treatments for human foveal and macular degenerative diseases in dogs.”