Biomaterial Database

Reactivity of the human retinal circulation to darkness: a laser Doppler velocimetry study. 1983

C E Riva, and J E Grunwald, and B L Petrig

Bidirectional laser Doppler velocimetry (LDV) and fundus photography were applied to investigate the effects of light and darkness on retinal blood flow. Blood flow had increased by an average of 67% after 5 min of darkness. This increase persisted for periods of darkness as long as 80 min (the longest period tested). The magnitude of this elevation, its time course, and its neutralization by the breathing of 100% O2 suggest that, in vivo, the retina consumes more O2 in the dark than in light. This effect is, most probably, associated with the maintenance of the photoreceptor dark current. LDV in light and darkness may become a useful probe of retinal function.

UI	MeSH Term	Description	Entries
D007834	Lasers	An optical source that emits photons in a coherent beam. Light Amplification by Stimulated Emission of Radiation (LASER) is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation. Lasers operate in the infrared, visible, ultraviolet, or X-ray regions of the spectrum.	Masers,Continuous Wave Lasers,Pulsed Lasers,Q-Switched Lasers,Continuous Wave Laser,Laser,Laser, Continuous Wave,Laser, Pulsed,Laser, Q-Switched,Lasers, Continuous Wave,Lasers, Pulsed,Lasers, Q-Switched,Maser,Pulsed Laser,Q Switched Lasers,Q-Switched Laser
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D001783	Blood Flow Velocity	A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.	Blood Flow Velocities,Flow Velocities, Blood,Flow Velocity, Blood,Velocities, Blood Flow,Velocity, Blood Flow
D003624	Darkness	The absence of light.	Darknesses
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012171	Retinal Vessels	The blood vessels which supply and drain the RETINA.	Pecten Oculi,Retinal Vasculature,Retinal Blood Vessels,Retinal Blood Vessel,Retinal Vasculatures,Retinal Vessel,Vasculature, Retinal,Vessel, Retinal,Vessel, Retinal Blood