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CHANGES IN ANGIOSCOTOMAS ASSOCIATED WITH INHALATION OF OXYGEN

CHANGES IN ANGIOSCOTOMAS ASSOCIATED WITH INHALATION OF OXYGEN Abstract In 1938 Evans and McFarland1 showed a relation between oxygen deprivation and angioscotomas. They demonstrated a widening of the defects, the extent of which varied with the degree of oxygen deprivation. They suggested that these changes arose because of a relative anoxemia at the synapses of the first and second retinal neurons. According to Peters and Van Slyke,2 the hemoglobin in the arterial blood of persons free from disorders of the respiratory tract has an oxygen saturation of approximately 95 to 96 per cent at sea level. The additional amount of oxygen that can be carried by the blood is small even when the oxygen tension in the inspired air is elevated. It corresponds at most to the remaining 5 per cent of the oxygen-carrying capacity of hemoglobin plus a small amount physically dissolved in the plasma (which is proportional to the arterial oxygen tension). It is generally References 1. Evans, J. N., and McFarland, R. A.: Effects of Oxygen Deprivation on Visual Fields , Am. J. Ophth. 21:968 ( (Sept.) ) 1938. 2. Peters, J. P., and Van Slyke, D. D.: Quantitative Clinical Chemistry , Baltimore, Williams & Wilkins Company, 1932, vol. 1, chap. 12. 3. One subject (chart 1, 6) had keratoconus; another (chart 2, 11) had an alternating exotropia measuring 25 prism diopters. 4. MSA Comfo respirator. 5. Evans, J. N. : An Introduction to Clinical Scotometry , New Haven, Conn., Yale University Press, 1938, chap. 6. 6. This physiologic scotoma may be explained as being due to a relative edema of the inferior portion of the retina as a result of its dependency. 7. Evans,5 chap. 13, p. 154. 8. Bellows, J. D., and Chinn, H.: Distribution of Sulfanilamide in the Eye , J. A. M. A. 112:20 ( (May 20) ) 1939. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Archives of Ophthalmology American Medical Association

CHANGES IN ANGIOSCOTOMAS ASSOCIATED WITH INHALATION OF OXYGEN

Archives of Ophthalmology , Volume 22 (3) – Sep 1, 1939

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Publisher
American Medical Association
Copyright
Copyright © 1939 American Medical Association. All Rights Reserved.
ISSN
0003-9950
eISSN
1538-3687
DOI
10.1001/archopht.1939.00860090051005
Publisher site
See Article on Publisher Site

Abstract

Abstract In 1938 Evans and McFarland1 showed a relation between oxygen deprivation and angioscotomas. They demonstrated a widening of the defects, the extent of which varied with the degree of oxygen deprivation. They suggested that these changes arose because of a relative anoxemia at the synapses of the first and second retinal neurons. According to Peters and Van Slyke,2 the hemoglobin in the arterial blood of persons free from disorders of the respiratory tract has an oxygen saturation of approximately 95 to 96 per cent at sea level. The additional amount of oxygen that can be carried by the blood is small even when the oxygen tension in the inspired air is elevated. It corresponds at most to the remaining 5 per cent of the oxygen-carrying capacity of hemoglobin plus a small amount physically dissolved in the plasma (which is proportional to the arterial oxygen tension). It is generally References 1. Evans, J. N., and McFarland, R. A.: Effects of Oxygen Deprivation on Visual Fields , Am. J. Ophth. 21:968 ( (Sept.) ) 1938. 2. Peters, J. P., and Van Slyke, D. D.: Quantitative Clinical Chemistry , Baltimore, Williams & Wilkins Company, 1932, vol. 1, chap. 12. 3. One subject (chart 1, 6) had keratoconus; another (chart 2, 11) had an alternating exotropia measuring 25 prism diopters. 4. MSA Comfo respirator. 5. Evans, J. N. : An Introduction to Clinical Scotometry , New Haven, Conn., Yale University Press, 1938, chap. 6. 6. This physiologic scotoma may be explained as being due to a relative edema of the inferior portion of the retina as a result of its dependency. 7. Evans,5 chap. 13, p. 154. 8. Bellows, J. D., and Chinn, H.: Distribution of Sulfanilamide in the Eye , J. A. M. A. 112:20 ( (May 20) ) 1939.

Journal

Archives of OphthalmologyAmerican Medical Association

Published: Sep 1, 1939

References