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Show }. Clin. Neuro-ophthalmol. 3: 283-284, 1983. In 1926, Prof. Dr. Hermann Wilbrand described the anterior projection of the crossing nasal retinal fibers into the contralateral optic nerve just adjacent to the chiasm. l He stated the fibers formed a "knee," thus leading to the popular term of "genu" or "knee of Wilbrand." Autopsy specimens of the optic nerve, chiasm, and optic tracts of patients with normal optic nerves and patients with unilateral optic atrophy were compared in his masterful Neuro-anatomical Feature Photo LENORE A. BREEN, MD. FRANK C. QUAGLIERI, MD. SYDNEY S. SCHOCHET, JR., MD. anatomical study. Later necropsy studies correlating visual field defects (junction scotoma) with tumor locations have suggested indirectly that the genu is primarily inferior nasal in origin.2 We recently completed an autopsy study of a 43-year-old man who died after coronary bypass surgery. By history, he lost his right eye soon after birth for an unknown reason. The right optic nerve was obviously atrophic on gross examination Figure 1. See text. From the Departments of Neurology (LAB, FCQ, SSSJ, Ophthalmology (LAB), and Pathology (SSSJ, West Virginia University School of Medicine, Morgantown, West Virginia. December 1983 (Fig. 1). A section through the optic nerves, chiasm, and tracts stained with Luxol fast blue reveals only a loop or "knee" of stained fibers present in the 283 Neuro-anatomical Feature Photo Figure 2. See text. otherwise unstained right optic nerve at its junction with the chiasm (Fig. 2). There is also a suggestion of pallor in the corresponding area of the normal optic nerve. References 1. Wilbrand, H.: Schema des Verlaufs der Sehnervenfasern durch das Chiasma. Zeitschr. f. Augenheilk. 59: 135, 1926. 284 2. Miller, N.R.: Walsh and Hoyt's Clinical Neuro-Ophthalmology (4th ed.). Williams & Wilkins, Baltimore, 1982, p. 65. Write for reprints to: Sydney 5. 5chochet, Jr., M.D., Department of Pathology, West Virginia University Medical Center, Morgantown, West Virginia 26506. Journal of Clinical Neuro-ophthalmology |