Abstract
Abstract The optic axis of the globe only exceptionally coincides with the visual axis. The angle formed by these two axes has had several denominations, according to the points of reference. Thus the angle formed by these two axes when their intersection is at the nodal point of the eye had been called angle alpha by Helmholtz.1 The angle formed by the line uniting the rotation center of the eye to the point of fixation with the optic axis is the angle gamma (Donders2). The angle formed by the central pupillary line, that is, a line perpendicular to the cornea and passing through the center of the pupil and the visual axis, is the angle kappa (Landolt3 ). Helmholtz' angle alpha was called beta by Brubaker,4 and Landolt's angle kappa was christened delta by Howe.5 In 1866 Helmholtz6 himself gave a definition of angle alpha, according References 1. Helmholtz, H. : Helmholtz's Treatise on Physiologic Optics , translated from the third German edition by J. P. C. Southall, Ithaca, N. Y., The Optical Society of America, 1924. 2. Donders: On the Anomalies of Accommodation and Refraction of the Eye , translated by W. D. Moore, London, New Sydenham Society, 1864. 3. Landolt, E., and Landolt, M.: Defective Ocular Movements and Their Diagnosis , translated by A. Roemmele and E. W. Brewerton, London, Oxford University Press, 1914. 4. Brubaker, in Duke-Elder,8 p. 759. 5. Howe, cited by Cords, R., in Schieck, F., and Brückner, A.: Kurzes Handbuch der Ophthalmologie , Berlin, Julius Springer, 1930, vol. 3, p. 468. 6. Helmholtz, in Duke-Elder,8 p. 759. 7. Landolt, in Duke-Elder.8 8. Duke-Elder, W. S.: Textbook of Ophthalmology , London, Henry Kimpton, 1932, vol. 1, p. 760. 9. Dashevsky, A. I., and Booshmitch, D. G.: Optical Decentration of the Eye , Am. J. Ophth. 21:125 ( (Feb.) ) 1938. 10. Howe,5 p. 740. 11. Alvaro, M. E.: Apparelhos para medição do estrabismo , in Actas Cong. argent. de oftal., Buenos Aires , 1937, vol. 1, p. 392. 12. This preparation is a combination of cinchophen sodium (0.5 Gm.), sodium salicylate (0.5 Gm.) and procaine hydrochloride (0.008 Gm.) in 5 cc. of solvent. 13. Comberg, W. : Ein neues Verfahren zur Röntgenlokalisation am Augapfel , Arch. f. Ophth. 118:175, 1927.
Journal
Archives of Ophthalmology
– American Medical Association
Published: Dec 1, 1939