Oxygen saturation in central retinal vein occlusion.
OBJECTIVE
To test whether oxygen saturation is affected in retinal blood vessels in patients with central retinal vein occlusion (CRVO).


METHODS
Prospective observational case series.


METHODS
Oxygen saturation of hemoglobin was measured in retinal blood vessels in 10 patients with unilateral CRVO. The duration of CRVO before measurement was from 1 day to about 6 months. Two patients were excluded because of poor quality of oximetry images. The spectrophotometric retinal oximeter is based on a fundus camera. It simultaneously captures images of the retina at 605 nm and 586 nm and calculates optical density (absorbance) of retinal vessels at both wavelengths. The ratio of the 2 optical densities is approximately linearly related to hemoglobin oxygen saturation. Mean oxygen saturation was calculated for first- and second-degree arterioles and venules in both eyes of each patient.


RESULTS
The mean oxygen saturation of hemoglobin in retinal venules was 49% ± 12% (mean ± SD, n = 8) in eyes affected by CRVO and 65% ± 6% in unaffected fellow eyes (P = .003). The mean arteriolar oxygen saturation was 99% ± 3% in CRVO eyes and 99% ± 6% in the fellow eyes. Venular oxygen saturation was variable within and between CRVO eyes.


CONCLUSIONS
Oxygen saturation in retinal venules is lower in eyes with CRVO than in fellow eyes and there is considerable variability within and between CRVO eyes. Arteriolar saturation is the same in CRVO and fellow eyes. Retinal oxygenation is disturbed in CRVO.
Hardarson
Sveinn Hakon
SH
Department of Ophthalmology, University of Iceland/Landspítali-University Hospital, Reykjavik, Iceland.
Stefánsson
Einar
E
D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology; D011446:Prospective Studies; D012161:Retinal Artery / Q000503:physiopathology; D012169:Retinal Vein / Q000503:physiopathology; D012170:Retinal Vein Occlusion / Q000503:physiopathology*
D006454:Hemoglobins; D010100:Oxygen