TITLE

Changes in central retinal artery blood flow after ocular warming and cooling in healthy subjects

AUTHOR(S)
Shamshad, M. A.; Amitava, A. K.; Ahmad, I.; Wahab, S.
PUB. DATE
March 2010
SOURCE
Indian Journal of Ophthalmology;Mar2010, Vol. 58 Issue 3, p189
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Context: Retinal perfusion variability impacts ocular disease and physiology. Aim: To evaluate the response of central retinal artery (CRA) blood flow to temperature alterations in 20 healthy volunteers. Setting and Design: Non-interventional experimental human study. Materials and Methods: Baseline data recorded: Ocular surface temperature (OST) in °C (thermo-anemometer), CRA peak systolic velocity (PSV) and end diastolic velocity (EDV) in cm/s using Color Doppler. Ocular laterality and temperature alteration (warming by electric lamp/cooling by ice-gel pack) were randomly assigned. Primary outcomes recorded were: OST and intraocular pressure (IOP) immediately after warming or cooling and ten minutes later; CRA-PSV and EDV at three, six and nine minutes warming or cooling. Statistical Analysis: Repeated measures ANOVA. Results: (n 5 20; μ ± SD): Pre-warming values were; OST: 34.5 ± 1.02°C, CRA-PSV: 9.3 ± 2.33 cm/s, CRA-EDV: 4.6 ± 1.27 cm/s. OST significantly increased by 1.96°C (95% CI: 1.54 to 2.37) after warming, but returned to baseline ten minutes later. Only at three minutes, the PSV significantly rose by 1.21 cm/s (95% CI: 0.51to1.91). Pre-cooling values were: OST: 34.5 6 0.96°C, CRA-PSV: 9.7 μ 2.45 cm/s, CRA-EDV: 4.7 μ 1.12 cm/s. OST significantly decreased by 2.81°C (95% CI: -2.30 to -3.37) after cooling, and returned to baseline at ten minutes. There was a significant drop in CRA-PSV by 1.10 cm/s (95% CI: -2.05 to -0.15) and CRA-EDV by 0.81 (95% CI: -1.47 to -0.14) at three minutes. At six minutes both PSV (95% CI: -1.38 to -0.03) and EDV (95% CI: -1.26 to -0.02) were significantly lower. All values at ten minutes were comparable to baseline. The IOP showed insignificant alteration on warming (95% CI of difference: -0.17 to 1.57 mmHg), but was significantly lower after cooling (95% CI: -2.95 to -4.30 mmHg). After ten minutes, IOP had returned to baseline. Conclusion: This study confirms that CRA flow significantly increases on warming and decreases on cooling, the latter despite a significant lowering of IOP.
ACCESSION #
50282351

 

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics