Early-Onset Progressive Retinal Atrophy (PRA) is a genetically inherited eye disorder affecting dogs, characterised by the gradual deterioration of the retina, eventually leading to blindness. This condition is specifically termed "early-onset" to differentiate it from forms that appear later in a dog’s life. The early-onset form often begins affecting dogs in their youth or early adulthood.
The retina, which is the light-sensitive tissue lining the back of the eye, has cells called photoreceptors that convert light into electrical signals. These signals are sent to the brain and interpreted as visual images. In dogs with Early-Onset PRA, these photoreceptor cells begin to degenerate prematurely.
Symptoms typically start with night blindness. Affected dogs may show reluctance to go into dark spaces or are more hesitant at night. As the disease progresses, their daytime vision also deteriorates. Unfortunately, there is no current cure for PRA, and the condition leads to complete blindness.
Genetic testing can identify dogs that carry genes for PRA, which is crucial for breeders to prevent passing the condition to offspring.