Progressive retinal atrophy (PRA) is an inherited disease that causes non-painful, slowly progressive blindness. A common history is gradual loss of night vision followed by loss of day vision. This is because the disease first affects rods (retinal cells responsible for night vision) and then affect cones (retinal cells responsible for day vision). It typically affects middle-aged to older dogs. It is a non-painful condition and due to the slow onset most pets adjust to live a good quality of life with limited or no vision.
Genetics play a vital role in the disease, so 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.
There is no known treatment for PRA. The use of antioxidant therapy may help slow this process, but there is no therapy that can halt the disease progression entirely. Neutraceuticals may serve as antioxidants for retinal health and potentially minimize cataract formation.
Note that as a retina degenerates, materials can be released in the eye that promote cataract formation and inflammation, so your pet should continue to be seen by an ophthalmologist as he/she may require anti-inflammatory medications or other therapy in the future. Ocular inflammation may be painful and may lead to glaucoma.