title: [Foveolar aplasia in tyrosinase-positive oculocutaneous albinisim (author's transl)].
abstract: The eye of a 47 year old man with tyrosinase-positive oculocutaneous albinism, photophobia, nystagmus and visual acuity 0, 4-0, 5 was histologically examined after orbital exenteration for neoplasia. Histologic serial sections of the centre of the retina showed a continuous 6-8 cell-layer of ganglion cells, without any suggestion of a foveolar pit. The outer layers of the macular retina were altered secondarily by tumor-impression-folds; they were unremarkable at the periphery as were the acid mucopolysaccharides in the receptor region. Electron microscopy of the uvea and the retinal pigment epithelium showed a normal number of pigment granules but a deficiency of melanin, as well as structural anomalies. The absence of the foveolar pit and the decrease of visual acuity in tyrosinase-positive albinism is caused by definite morphologic alteration in the arrangement of ganglion cells in the macular region in the sense of a foveolar aplasia. The etiology is discussed. An identic anomaly has been described in aniridia, similar ones in other congenital ocular diseases.
mesh_terms: D000417:Albinism / Q000378:metabolism / Q000473:pathology*; D004156:Catechol Oxidase / Q000032:analysis; D005584:Fovea Centralis / Q000473:pathology*; D005724:Ganglia / Q000473:pathology; D006801:Humans; D008266:Macula Lutea / Q000473:pathology*; D008297:Male; D008543:Melanins / Q000032:analysis; D008875:Middle Aged; D010857:Pigment Epithelium of Eye / Q000032:analysis / Q000648:ultrastructure; D012160:Retina / Q000473:pathology; D014602:Uvea / Q000032:analysis / Q000473:pathology
chemical_list: D008543:Melanins; D004156:Catechol Oxidase
vernacular_title: Foveola-Aplasie bei Tyrosinase-positivem oculocutanen Albinismus. Klinish-pathologische Befunde