Retinal blood velocities during carbogen breathing using scanning laser ophthalmoscopy

Oliver Arend, Alon Harris, Bruce J. Martin, Mary Holin, Sebastian Wolf

Research output: Contribution to journalArticlepeer-review

29 Scopus citations


Abstract. Hyperoxic‐hypercapnic gas mixture (‘carbogen’: 6% CO2‐94% O2) is widely used clinically. Its influence on retinal perfusion remains unclear, since past work suggests that high O2 may reduce and high CO2 may increase retinal blood flow. To examine the changes in retinal blood velocity during ‘hyperoxic‐hypercapnic’ gax mixture breathing, we quantified retinal blood velocity indices. Twenty‐eight healthy subjects were studied using scanning laser video fluorescein angiograms at baseline and after gas inhalation. Retinal arteriovenous passage time and mean arterial dye velocity were measured by means of a digital image processing system. Arterial diameter measurements showed no change (4%) during carbogen breathing. Increased arterial Pco2 and Po2 resulted in small but statistically significant increases in systolic and diastolic blood pressure and heart rate (each c. 8%, p < 0.05), and a dramatic increase in mean dye velocity (27%, p < 0.01), with parallel reduction in arteriovenous passage time (40%, p < 0.01). The substantial acceleration of retinal dye velocity and transit under combined hyperoxia and hypercapnia strongly suggests that this clinically standard gas mixture may indeed improve oxygenation without reducing retinal perfusion. 1994 Institution Acta Ophthalmologica Scandinavica

Original languageEnglish
Pages (from-to)332-336
Number of pages5
JournalActa Ophthalmologica
Issue number3
StatePublished - Jun 1994
Externally publishedYes


  • carbon dioxide
  • central artery occlusion
  • microcirculation
  • oxygen
  • retina


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