The occurrence of binasaI hemianopia, not only in tabes dorsalis but from any cause, is rare. Mooren1 saw only 5 cases of the binasal form in 125,000 patients with ocular conditions. Schweigger2 found 1 binasal defect in 39 cases of hemianopia. Lutz3a published an analysis of 84 cases of binasal hemianopia reported in the literature. In a later article,3b reports of 9 additional cases were published. Lutz stated that the causes of binasal hemianopia include cerebral tumors, changes in the vessels, acute inflammatory processes, cerebral syphilis, tabes dorsalis, trauma and hysteria. I shall consider here only the form due to the tabetic process.
Clinically, the atrophy of the optic nerve which occurs in tabes dorsalis appears in the preataxic stage and is often present in cases which show a paucity of neurologic signs. The onset of the visual failure is, in a vast majority of cases,