title: Observation and characterization of microvascular vasomotion using erythrocyte mediated ICG angiography (EM-ICG-A).
abstract: A clinical method for characterizing the state of micro-vasculature vasomotion is demonstrated, based on observing in capillaries the dynamics of autologously re-injected erythrocytes containing ICG dye. Since a manifestation of vasomotion is transient erythrocyte pausing, vasomotion state within a field of capillaries is characterized by an histogram plot of the number of paused erythrocytes as a function of pause duration during a fixed period of observation, then the ratio of long-pausing to short-pausing erythrocytes was calculated. The method was first applied to the posterior pole retinal vasculatures of anesthetized-monkey eyes, and normal vasomotion state during air-breathing was compared to the state induced by O2-breathing, known to cause mild arteriolar vasoconstriction in the mature eye. Subsequently, the effects of other antagonists to normal arteriolarvasotonia state (long-standing experimentally-induced ocular hypertension and branch-vein occlusion, as well as tissue edema) were similarly characterized and the results compared to those obtained during baseline air-breathing. The feasibility of applying the histogram characterization of vasomotion state to human eyes and skin was also preliminarily explored.
authors.affiliation: New York University School of Medicine, USA; University of Maryland School of Medicine, USA. Electronic address: rwflower@verizon.net.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Flower
authors.forename: Ronn
authors.initials: R
authors.lastname: Kling
mesh_terms: D000792:Angiography / Q000379:methods*; D000818:Animals; D001783:Blood Flow Velocity; D004195:Disease Models, Animal; D004912:Erythrocytes / Q000378:metabolism*; D005240:Feasibility Studies; D005456:Fluorescent Dyes / Q000008:administration & dosage / Q000378:metabolism*; D000882:Haplorhini; D006439:Hemodynamics; D006801:Humans; D007208:Indocyanine Green / Q000008:administration & dosage / Q000378:metabolism*; D008833:Microcirculation; D055806:Microvessels / Q000503:physiopathology*; D009798:Ocular Hypertension / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D011237:Predictive Value of Tests; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D012170:Retinal Vein Occlusion / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D012171:Retinal Vessels / Q000503:physiopathology*; D012867:Skin / Q000098:blood supply*; D013997:Time Factors
chemical_list: D005456:Fluorescent Dyes; D007208:Indocyanine Green