Progressive retinal atrophy (rcd4-PRA) / LOPRA
Progressive retinal atrophy (PRA) is a major hereditary cause of blindness in pedigree dogs as is its counterpart retinitis pigmentosa (RP) in humans. PRA shows genetic heterogeneity, as does RP, with several distinct forms already recognized and several more remaining to be investigated.
One can distinguish between late onset forms of PRA and early onset (whelp-age) dysplastic changes. The clinical and ophthalmologic signs of both forms are similar. Affected dogs suffer from bilateral Mydriasis, the reflection of the Tapetum lucidum is increased and the retinal vascular network appears atrophic.
The rcd4 PRA is another form of PRA, it is also known as LOPRA (Late Onset PRA) the age of onset of dogs with LOPRA varies from few years of age (2-3 years) up to old age (10-11 years)