Retrobulbar haemodynamics and contrast sensitivity improvements after CO2 breathing

• Published in: Acta ophthalmologica Scandinavica 2006-08, Vol.84 (4), p.481-487
• Main Authors: Huber, Klaudia K., Adams, Herbert, Remky, Andreas, Arend, Kay O.
• Format: Article
• Language: English
• Subjects: Adult; blood flow; Blood Flow Velocity; Blood Pressure - physiology; carbon dioxide; Carbon Dioxide - administration & dosage; colour Doppler imaging; contrast sensitivity; Contrast Sensitivity - physiology; Eye - blood supply; Female; Heart Rate - physiology; Hemodynamics - physiology; Humans; hypercapnia; Hypercapnia - physiopathology; Intraocular Pressure - physiology; Male; Middle Aged; Ophthalmic Artery - physiology; Oxygen - blood; Prospective Studies; Retinal Artery - physiology; Ultrasonography, Doppler, Color; Vasodilation - physiology
• ISSN: 1395-3907; 1600-0420
• DOI: 10.1111/j.1600-0420.2006.00687.x

. Purpose:  Effects of gas mixtures have been widely studied. Carbon dioxide (CO2) is known to act as a vasodilator, whereas oxygen (O2) acts as a vasoconstrictor. Therefore, the interpretation of results is difficult. In this study, only the effect of an elevated CO2 level on retrobulbar hemodynamics and contrast sensitivity was investigated. Methods:  Thirty adults (age 31 ± 7) were examined under normocapnic and hypercapnic conditions. Colour Doppler imaging was used to measure the velocity in the ophthalmic and central retinal artery. Moreover, contrast sensitivity using the CSV‐1000 was investigated. Blood pressure, heart rate and intraocular pressure (IOP) were measured and ocular perfusion was calculated. Results:  Under hypercapnia, mean end tidal CO2 increased from 36.4 mmHg to 42.5 mmHg and blood oxygen saturation increased from 98.3% to 98.6% (p