[Localized forms of retinopathia pigmentosa]

Classification of localized forms of peripheral retinitis pigmentosa can be performed according of the pigmented areas: Unilateral RP (URP): Probably a phenocopy. It mimics typical RP clinically and electrophysiologically in one eye, sparing the fellow eye. Sector RP (SRP): Bone corpuscle-like intraretinal pigmentations a cover a fundus sector (mainly the lower half of the fundi). Corresponding field defects. Progressive paravenous retinochoroidal atrophy (PPRCA): Paravenous distribution of retinal pigmentations. Tongue-shaped field defects. Peripapillary RP (PPD): Pigmentary retinal deposits in the area surrounding the optic disc. Corresponding field defects. Electrophysiology is an important tool in the diagnosis of localized forms of retinitis pigmentosa: The amount of reduction of ERG amplitudes corresponds to the pigmented retinal area. The impaired EOGs indicate a general involvement of the retinal pigment epithelium. In contrast, acquired-e.g. postinflammatory or circulatory-processes display normal EOGs.