[Animal models for retinitis pigmentosa research]

Retinitis pigmentosa (RP) is the general term given to a group of genetically determined, degenerative retinal diseases which afflict some 1.5 million humans worldwide. Molecular genetic studies in recent years have shown that RP cannot be explained by a single genetic defect but rather that the hereditary aberration responsible for triggering the onset of the disease is localized in different genes and at different sites within these genes. A fuller understanding of these processes is possible only if the pathogenesis of the diseases can be followed as they develop. Animal models are an indispensable requirement for this. Only in the animal model is it possible to observe progressive degenerations in "time-lapse photography" as it were and to examine the biochemical, functional and morphological changes which appear at specific times in the retina. This article gives an overview of the animal models presently used in RP research, with a short description of genetic backgrounds and the progression of the disease in individual animals. In addition, a look at the future is provided of new molecular techniques which make it possible to create specific animal models with gene mutations identical to those appearing in human RP. Since hereditary human retinal degenerations can be brought about by numerous different genetic defects, comparative studies using animals with clearly defined genetic defects are essential. Only in this way is it possible to arrive at conclusions concerning this specialized syndrome and to clarify the mechanisms which are common to all retinal degenerations.