Clinical Trial: Effects of Vitamin C on Hyperoxia-Induced Reduction of Retinal Blood Flow
Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: Effects of Vitamin C on Hyperoxia-Induced Reduction of Retinal Blood Flow
Brief Summary:
High arterial blood oxygen tension leads to vasoconstriction of retinal vessels, possibly related to an interaction between reactive oxygen species and endothelium-derived vasoactive factors. Vitamin C is a potent antioxidant capable of reversing endothelial dysfunction due to increased oxidant stress. Vitamin C appears to have vasodilatory properties, but the underlying mechanisms are not well understood.
In the present study we hypothesized that hyperoxic vasoconstriction of retinal vessels could be diminished by vitamin C.
Ocular blood flow will be determined by non-invasive methods, including laser Doppler velocimetry and the Zeiss retinal vessel analyser.
Detailed Summary:
Sponsor: Medical University of Vienna
Current Primary Outcome:
- Retinal arterial and venous diameter (Zeiss retinal vessel analyzer) [ Time Frame: in total 6 hours ]
- Retinal blood flow velocity (laser Doppler velocimetry) [ Time Frame: in total 6 hours ]
- Intraocular pressure (applanation tonometry) [ Time Frame: in total 10 minutes ]
Original Primary Outcome: Same as current
Current Secondary Outcome:
Original Secondary Outcome:
Information By: Medical University of Vienna
Dates:
Date Received: July 8, 2008
Date Started: February 2003
Date Completion:
Last Updated: July 9, 2008
Last Verified: July 2008
