[Acquired black disc and melanotic retina after resection of an orbital meningioma (author's transl)].

Resection of an orbital meningioma in a 53-year-old patient caused an occlusion of the central retinal artery and total ophthalmoplegia. Eight weeks postoperatively rapid development of a black disc was observed with migration of pigment into the juxtapapillary retina. One year later the eye was removed during a radical reoperation. Histological and ultrastructural examination showed that the melanosis of the disc and the retina was apparently due to reactive proliferation of the juxtapapillary pigment epithelium which had migrated into the atrophic tissues of the retina and the disc. The histological differentiation from hamartomatous proliferations of the juxtapapillary pigment epithelium is discussed. The proliferated pigment epithelium cells in this patient resemble those described in epiretinal membranes apart from abundant RER and actin filaments. In the absence of mechanical or inflammatory factors it must be assumed that hypoxia was the stimulus responsible for the proliferation. The presence of fenestrated retinal capillaries in the proliferation zone is described and the significance of this finding is discussed.