Diffusion of O2 in normal and ischemic retinas of anesthetized miniature pigs in normoxia and hyperoxia

  • Constantin J. Pournaras
  • Marcos Tsacopoulos
  • Charles E. Riva
  • André Roth
Laboratory Investigations


TransretinalPO2 profiles were recorded with O2-sensitive microelectrodes in the normal retina and in ischemic retinal foci induced by the occlusion of a retinal branch vein with argon laser photocoagulation in anesthetized miniature pigs. In the normal retina there are twoPO2 gradients: one from the inner retina and the other from the choroid, both directed toward the middle of the retina. BothPO2 gradients persisted during hyperoxia. Thus, even in hyperoxia, the choroid does not supply the whole thickness of the normal retina with O2. Preretinal and transretinalPO2 measurements in ischemic inner retinal foci showed the existence of twoPO2 gradients in steady-state systemic normoxia, as did those in the normal retina. This finding indicates that even in ischemia the choroid does not supply O2 to the inner retina; as a result, tissue hypoxia is maintained. During systemic hyperoxia, the intraretinalPO2 measurements in the ischemic foci showed only one gradient going from the choroid toward the inner retina. This gradient indicates that under these conditions, the choroid can supply O2 to the entire thickness of the ischemic retina. Extending a previously formulated hypothesis, we propose that in the ischemic retina as opposed to the normal retina, hyperoxia does not induce an increase in the O2 consumption of the outer retina. This suggestion could explain the rise inPO2 in the inner ischemic retina during hyperoxia.


Retina Retinal Vein Occlusion Retinal Branch Vein Occlusion Normal Retina Transretinal 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Alder VA, Cringle SJ (1985) The effect of the retinal circulation on the vitreal oxygen tension. Curr Eye Res 4:121–129PubMedCrossRefGoogle Scholar
  2. 2.
    Alder VA, Cringle SJ, Constable IJ (1983) The retinal oxygen profile in cats. Invest Ophthalmol Vis Sci 24:30–36PubMedGoogle Scholar
  3. 3.
    Alder VA, Cringle SJ, Brown M (1987) The effect of regional retinal photocoagulation on vitreal oxygen tension. Invest Ophthalmol Vis Sci 28:1078–1087PubMedGoogle Scholar
  4. 4.
    Beauchemin ML (1974) The fine structure of the pig retina. Graefe’s Arch Clin Exp Ophthalmol 190:27–45CrossRefGoogle Scholar
  5. 5.
    Bloodworth JMB Jr, Gutgesell HP, Engermann RL (1965) Retinal vasculature of the pig: light and electron microscope studies. Exp Eye Res 4:174–178PubMedCrossRefGoogle Scholar
  6. 6.
    Danis RP, Wallow IHL (1987) Microvascular changes in experimental branch retinal vein occlusion. Ophthalmology 94:381–392Google Scholar
  7. 7.
    Dollery CT, Bulpitt CJ, Kohner EM (1969) Oxygen supply to the retina from the retinal and choroidal circulations at normal and increased arterial oxygen tensions. Invest Ophthalmol Vis Sci 8:588–594Google Scholar
  8. 8.
    Drujan BD, Svaetichin G (1972) Characterization of different classes of isolated retinal cells. Vision Res 12:1777–1783PubMedCrossRefGoogle Scholar
  9. 9.
    Flower RW, Patz A (1972) The effect of hyperbaric oxygenation on the retinal ischemia. Invest Ophthalmol Vis Sci 10:605–616Google Scholar
  10. 10.
    Landers MB (1978) Retinal oxygenation via the choroidal circulation. Trans Am Ophthalmol Soc 76:528–529PubMedGoogle Scholar
  11. 11.
    Linsenmeier RA (1986) Effects of light and darkness on oxygen distribution and consumption in the cat retina. J Gen Physiol 88:521–542PubMedCrossRefGoogle Scholar
  12. 12.
    Linsenmeier RA, Yansey CM (1986) Oxygenation of the cat retina: effects of hyperoxia (abstr). Invest Ophthalmol Vis Sci 27 [Suppl]:38Google Scholar
  13. 13.
    Lowry OH, Robert RN, Lewis C (1956) The quantitative histochemistry of the retina. J Biol Chem 220:879–892PubMedGoogle Scholar
  14. 14.
    Molnar I, Poitry S, Tsacopoulos M, Gilodi N, Leuenberger P (1985) Effect of laser photocoagulation on oxygenation of the retina in miniature pigs. Invest Ophthalmol Vis Sci 26:1410–1414PubMedGoogle Scholar
  15. 15.
    Pournaras CJ (1987) L’inhibition de l’ondeb de l’ERG local par l’hypercapnie: exploration au moyen des microélectrodes sensibles au K+ sur la rétine isolée de la grenouille (Rana ridibunda). Thèse 7081, Université de GenèveGoogle Scholar
  16. 16.
    Pournaras CJ, Ilic J, Gilodi N (1985) Physiopathologie de la circulation rétinienne: conséquences d’ une occlusion vasculaire rétinienne aiguë. Klin Monatsbl Augenheilkd 186:471–476PubMedGoogle Scholar
  17. 17.
    Pournaras CJ, Ilic J, Gilodi N, Tsacopoulos M, Leuenberger PM (1986) Occlusion veineuse expérimentale: le rôle de la rétine ischémique dans le dévelopment des néovaisseaux intra ou prérétiniens. Klin Monatsbl Augenheilkd 188:345–347Google Scholar
  18. 18.
    Pournaras CJ, Riva CE, Tsacopoulos M, Strommer K (1989) Diffusion of O2 in the retina of anesthetized miniature pigs in normoxia and hyperoxia. Exp Eye Res 49:347–360PubMedCrossRefGoogle Scholar
  19. 19.
    Riva CE, Pournaras CJ, Tsacopoulos M (1986) Regulation of local oxygen tension and blood flow in the inner retina during hyperoxia. J Appl Physiol 61:592–598PubMedGoogle Scholar
  20. 20.
    Rootman J (1971) Vascular system of the optic nerve head and retina in the pig. Br J Ophthalmol 55:808–819PubMedCrossRefGoogle Scholar
  21. 21.
    Tsacopoulos M, Baker R, Levy S, Munoz J-L (1975) A versatile system for studying mammalian intraretinal metabolism and function in situ. Exp Eye Res 21:47–57PubMedCrossRefGoogle Scholar
  22. 22.
    Tsacopoulos M, Baker R, Levy S (1976) Studies on retinal oxygenation. Adv Exp Med Biol 75:413–416PubMedGoogle Scholar
  23. 23.
    Tsacopoulos M, Beauchemin ML, Baker R, Babel J (1976) Studies of experimental retinal focal ischaemia in miniature pigs. Proceedings of the 3rd William Mackenzie Memorial Symposium. Henry Kimpton, London, pp 93–103Google Scholar
  24. 24.
    Tsacopoulos M, Lehmenkühler A (1977) A double-barrelled Pt microelectrode for simultaneous measurements ofPO2 and bioelectrical activity in excitable tissue. Experientia 3:1337–1338CrossRefGoogle Scholar
  25. 25.
    Tsacopoulos M, Poitry S, Borselino A (1981) Diffusion and consumption of oxygen in superfused retina of drone (Apis mellifera) in darkness. J Gen Physiol 77:601–628PubMedCrossRefGoogle Scholar
  26. 26.
    Wise GN, Dollery GT, Henkind P (1971) In: The retinal circulation. Harper and Row, New York, pp 187–282Google Scholar

Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • Constantin J. Pournaras
    • 1
  • Marcos Tsacopoulos
    • 1
  • Charles E. Riva
    • 2
  • André Roth
    • 1
  1. 1.University Eye Clinic and Experimental Ophthalmology LaboratoryGeneva 4Switzerland
  2. 2.Department of OphthalmologyUniversity of Pennsylvania and Scheie Eye InstitutePhiladelphiaUSA

Personalised recommendations