Progressive Retinal Atrophy (PRA) is an inherited disease in many canine breeds, and some feline breeds. The disease is a progressive loss of photoreceptor cell, responsible for vision. It may first affect dim light vision and eventually result in complete blindness. Since the vision loss is so gradual, most owners don't notice a problem until the blindness has progressed. There is no known treatment for PRA at this time. PRA is actually a collection of specific types of retinal degeneration depending on the breed so there are probably multiple causes.
Genetics play a vital role in the disease and therefore, individuals related to your pet should also be examined for PRA with an eye exam. Genetic testing is available for many breeds known to develop PRA. In some cases, an electroretinogram (ERG) can be performed. An ERG is a test of retinal function, and may indicate PRA prior to obvious vision changes.
Most patients adjust to blindness with time and there is no need to make many changes other than keeping the environment stable. PRA is neither a painful nor life-threatening disease.
There are books available to help you become a better “seeing eye person” for your pet. “Doggles” can help to protect the eyes from injury.