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Gases and the ocular vasculature
Author(s) -
SCHMETTERER L
Publication year - 2010
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2010.2221.x
Subject(s) - optic nerve , blood flow , choroid , vasodilation , medicine , retina , pulsatile flow , hypoxia (environmental) , vascular tone , anesthesia , ophthalmology , chemistry , biology , neuroscience , oxygen , organic chemistry
Purpose The regulation of ocular blood flow and oxygenation is largely controlled by metabolic factors. Among them gases like oxygen (O2), carbon dioxide (CO2), carbon monoxide (CO) and nitroc oxide (NO) play a key role. Methods In a series of clinical trials we focussed on the role of O2, CO2, CO and NO in the control of ocular blood flow. These studies were done on healthy subjects and employed a number of techniques including laser Doppler flowmetry, color Doppler imaging and pulsatile ocular blood flow techniques. Results O2 is a very potent vasoconstrictor in the retina and optic nerve head, but not in the choroid. The mechanisms underlying this effect is not entirely clear, but appears to involve endothelin A receptors. CO and CO2 are potent vasodilators in retina, choroid and optic nerve head. NO plays a major role in the control of basal vascular tone in all ocular vessels, but is also involved in many agonist‐induced vasodilator effects. Conclusion Gases play a key role in controlling ocular blood flow. An imblanace of the production of these mediators is associated with ischemia, hypoxia and endothelial dysfunction.