[Hereditary retinochoroidal dystrophies. Part 1: Pathogenesis, diagnosis, therapy and patient counselling].

Hereditary retinochoroidal dystrophies are a heterogeneous group of disorders characterised by progressive loss of visual acuity or visual field. They can manifest at every age of life. The basic knowledge of retinal physiology and pathophysiology, diagnostic approach, therapeutic limitations and patient counselling are summarised. Hereditary retinochoroidal dystrophies are usually monogenic disorders. The diagnosis is based on a combined assessment of patient history and the results of morphological, electrophysiological, psychophysical and molecular genetic evaluations. Patients should undergo measurement of refraction and visual acuity testing, perimetry, ophthalmoscopy, full-field and multifocal electroretinography. Additional methods, e.g. fluorescein angiography, electrooculography or laboratory testing are helpful in certain cases. For promising new methods like measurement of retinal pigment epithelium autofluorescence or optic coherence tomography further evaluation of their value for differential diagnosis is required. General molecular genetic testing is still limited due to technical and financial limitations. A detailed differential diagnosis and long-term follow-up are advisable for patient counselling and the development of new therapeutic options. To date, therapy is limited. Major tasks for the ophthalmologists are providing low vision aids and adequate patient counselling.