Details

Autor(en) / Beteiligte

• Polska, Elzbieta
• Kircher, Karl
• Ehrlich, Paulina
• Vecsei, Pia V
• Schmetterer, Leopold

Titel

RI in central retinal artery as assessed by CDI does not correspond to retinal vascular resistance

Ist Teil von

• American journal of physiology. Heart and circulatory physiology, 2001-04, Vol.280 (4), p.H1442-H1447

Ort / Verlag

United States

Erscheinungsjahr

2001

Quelle

MEDLINE

Beschreibungen/Notizen

• 1  Department of Clinical Pharmacology and 2  Department of Ophthalmology, 3  Institute of Medical Physics, Vienna University, A-1090 Vienna, Austria The aim of the present study was to investigate the association between ultrasound Doppler measurements of resistive index (RI) in the central retinal artery and retinal vascular resistance ( R ) assessed with laser Doppler velocimetry, vessel size measurement, and calculation of ocular perfusion pressure (PP) in healthy subjects. An increase in vascular resistance was induced by inhalation of 100% O 2 . During hyperoxia no significant changes in PP were observed. Mean flow velocity in main retinal veins was reduced by 27.5   ± 2.0%. The average decrease in diameter was 11.5 ± 1.0%. R , which was calculated as the ratio of PP to flow rate, increased by 97.6 ± 7.7%. RI increased as well, but the effect was much smaller (6.6 ± 2.2%). In addition, a negative correlation was found between baseline values of R and RI ( r = 0.83). During hyperoxia R and RI were not associated. In conclusion, our data indicate that RI as assessed with color Doppler imaging in the central retinal artery is not an adequate measure of R . retinal blood flow; mean flow velocity; venous diameter; hyperoxia