Laser Doppler flowmetrie on small animal

Abstract

AbstractWe present a compact fundus camera designed to measure the blood flow in small animals based on laser Doppler flowmetry (LDF). The small animal is immobilized on a modified stereotaxic table and the pupil of the LDF device is superposed by translation to the pupil’s eye of the animal. Then rotation centered at the pupil is used to point the probing beam to the optic nerve head (ONH) or on retinal arteries (RA). LDF parameters Vel, Vol and F were assessed with a rotating teflon wheel simulating Doppler signal. Experiments were conducted on anesthetized adult male Wistar and Brown Normay rats. We demonstrated stable LDF parameters over 1 hours on RA and optic ONH for 6 and 10 rats respectively. Reproducibility is good for Vel on RA and ONH and moderate for Vol and F ONH. Transient ocular blood flow was blocked by increasing intra‐ocular pressure (IOP). Vel decreases significantly by 70% of baseline. Vel on RA was recorded during rat euthanasia. Vel decreases to the same level as for increased IOP. Vel measurement on RA are feasible, however measurement on ONH are more difficult probably due to a scare capillary network.