Sub-foveal choroidal blood flow by LDF: measurement and application to the physiology and pathology of the choroidal circulation.

Laser Doppler flowmetry allows the measurement of relative choroidal blood flow in the sub-foveal region of the fundus (ChBF). This technique has been applied to the investigation of the regulation of ChBF in response to a variety of physiological stimuli (breathing different gas mixtures of O2 and CO2, varying the systemic and ocular blood perfusion pressures, light-dark transition and zero gravity) in normal subjects. Measurements in pathological conditions, such as diabetes, age-related macular degeneration and glaucoma indicate alterations of the response of ChBF to increased systemic blood pressure. The data provide a better understanding of the regulation of the choroidal circulation in the normal and diseased eye.