The influence of ocular pulatility on canning laer Doppler flowmetry Original Reearch Article

PURPOE: To determine the effect of the cardiac cycle on canning laer Doppler flowmeter meaurement of retinal capillary blood flow in rheu monkey and human. METHOD: Multiple canning laer Doppler flowmetry image of rheu monkey and human retinal capillary blood flow over a range of heart rate were obtained. Average flow value were determined for the 64 can line that compoe the two-dimenional flow map. Cutaneou blood flow wa meaured imultaneouly with a laer Doppler flowmeter. The temporal relationhip between retinal capillary blood flow, peripheral arterial pule, and cutaneou blood flow were determined. In addition, human retinal capillary blood flow in a 10 × 10-pixel area during different phae of the cardiac cycle wa compared. REULT: Regular ocillation in human and rheu monkey retinal capillary blood flow are evident a alternating bright and dark horizontal band in canning laer Doppler flowmetry image. Thee fluctuation are temporally correlated with cutaneou blood flow. Linear regreion of actual v predicted heart rate baed on peak in retinal capillary flow yielded r = 0.999 in a rheu monkey and 0.938 in a human. Retinal capillary blood flow in a 10 × 10-pixel area fluctuated a much a 50% depending on the phae of the cardiac cycle. CONCLUION: The alternating bright and dark banding pattern oberved in canning laer Doppler flowmetry can of retinal capillary blood flow i related to the cardiac pule. The error introduced by pule-related fluctuation in retinal capillary blood flow are ignificant and mut be minimized or corrected for accurate and reproducible meaurement of ocular hemodynamic.