Retinal Blood Flow Measurements Using the Blue Field Entoptic Phenomenon: Does Perceived Leukocyte Velocity Depend on Contrast and Illuminance?

Abstract

Noninvasive quantification of blood flow velocity in retinal macular capillaries is possible now by using the blue field simulation technique (BFST).1The technique is based on the blue field entoptic phenomenon, which allows the observation of one's own leukocytes (white blood cells, WBCs) moving in retinal capillaries. To measure the velocity of these WBCs, a precisely controlled computer generated replica of the phenomenon is presented on a color graphics monitor. The subject is asked to adjust the number and velocity of the simulated WBCs to match those of the entoptically perceived WBCs.