What is the function of the retina?
The retina is a light sensitive layer of cells at the back of the eye that contains cells called photoreceptors. When light enters the eyes, it is focused by the lens onto the retina, where it is converted into electrical signals that are sent to the brain for processing and interpretation.
The two main photoreceptor cells of the retina are the rod cells and the cone cells. The dogs eyes contain many more rods than cones. Rod cells are responsible for vision in low light conditions and for detecting and following movement. Cone cells are responsible for detecting color. Cone cells do not work very well in low light.
Atrophy means the partial or complete wasting of a body part. Progressive retinal atrophy (PRA), is a group of degenerative diseases that affect these photoreceptor cells. With this disease, the cells deteriorate over time, eventually leading to blindness in the affected dog.
What Is Progressive Retinal Atrophy?
Progressive retinal atrophy is the degeneration of the retina (the rear layer of the eye). It primarily affects the cells of the retina called rods and cones, which pick up light, movement, and color. It can also degrade the pigmented epithelium layer that helps protect the rods and cones. Eventually, the degradation of these ocular surfaces leads to blindness.
Progressive Retinal Atrophy: Why It Matters to You
Some conditions are rare and a pet has as much chance of developing them as you have of winning the lottery. Sadly, PRA is not one of those conditions.
In some breeds, 1 out of every 5 puppies has the gene coding for PRA. These 20%-ers include Poodles, Nova Scotia Duck Tolling Retrievers and American Cocker Spaniels. And would it surprise you to learn that 1 in 6 Labrador Retrievers has the gene for PRA?
This means those of you with certain purebred dogs, those of you thinking about getting a dog and those of you who are breeders all should be aware of progressive retinal atrophy.
Quite simply, if breeders test their breeding stock and people refused to buy puppies from untested parents, then the distress of this blindness could be wiped out within a few generations.
In addition, you should be aware of the signs of PRA so you can help your dog adjust if they do have failing eyesight.
Let’s get things straight: There is no treatment or cure for progressive retinal atrophy in dogs.
But rather than bury your head in the sand, it’s important to spot the early signs. By doing so, you can help your dog adjust, and make the most of their failing eyesight to learn new ways of coping in the home and out on walks.