What is progressive retinal atrophy?
Progressive retinal atrophy is an incurable, but not painful, disease of the retina that results in complete loss of vision (blindness).
What happens in the dog's eye during progressive retinal atrophy?
In a normal eye, during vision, the light passes through the front part of the eye before reaching the retina. The retina is the light-sensitive layer at the back of the eye and it can be thought of as a little like the film of a camera. Light sensitive cells in the retina called cones and rods transform light into an electrical signal that travels along the optic nerve to reach the brain, where the electrical message is translated into an image which the animal sees.
Animation on the anatomical section of the eye
Retina anatomy:
During progressive retinal atrophy, the cones and rods degenerate and die, light is no longer transformed into an electrical signal and vision is therefore gradually affected.
How will I know my dog is going blind?
As its name suggests, this disease is progressive; the animal can adapt and behave normally at the onset of the disease. It is possible that cone-rod degeneration may take months or years to reach a point where a dog can no longer compensate for or 'hide' its loss of vision. Loss of vision can therefore appear to come on really suddenly after the disease has been progressing slowly for some time.
How will my vet make the diagnosis?
Diagnosis of progressive retinal atrophy is made by direct examination of the back of the eye using an instrument called an ophthalmoscope and also by an electroretinogram (ERG). An ERG is an electrical test of retinal activity.
Image of a normal dog eye fundus:
Fundus image of a dog with retinal atrophy:
Which dogs are affected by this pathology?
Progressive retinal atrophy is an inherited disease of the retina in many breeds of dog such as:
- Miniature Poodles
- Schnauzers
- Yorkshire Terriers
- Cocker spaniels
- Irish Setters
- Collies
What is the treatment?
There is currently no treatment or cure for progressive retinal atrophy. However, most dogs and cats can adapt relatively well to their blindness if their environment is not continually changed.
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