[Congenital grouped pigmentation of the retina (author's transl)].

In this disease entity we usually encounter black, sharply demarcated pigmented patches, occurring in groups and increasing in size toward the periphery. In the majority of cases the anomaly is unilateral (84%). The pigmentation may be found in one single sector (59%), in several separate sectors (27%) or distributed over the entire fundus (11%). Histology reveals pigment epithelial cells with hypertrophy and distinct irregularity in size and shape being arranged in one or two layers. Hyperpigmentation also exists with pigment granules of various size and distribution.