Amaurosis congenita of Leber is a hereditary optic neuropathy, usually bilateral, that quickly leads to blindness. There is no effective treatment. The inflammatory aspect of the papillary lesions in the early stage, in addition to the beneficial effect of plasma exchanges reported for other optic neuritides, led us to propose such a therapeutic regimen to 6 young adult men afflicted with the disease. This treatment was initiated early, before optic nerve atrophy occurred. The plasma volume exchanged was 3.2 +/- 0.5 liters/session and 4.2 +/- 1.8 (3 to 7) exchanges were performed. The exchanges were always well tolerated. Three patients subjectively reported improvement immediately following the exchanges but only one had some improvement of his visual acuity. However, a more sensitive evaluation of the ability to distinguish contrasts revealed improvement in patients whose visual acuity remained unchanged. This visual gain was lost 3 months later. Therefore, it appears that plasma exchanges are not the treatment of choice for this disease.