The Influence of Posture Change on Ocular Blood Flow in Normal Subjects, Measured by Laser Speckle Flowgraphy

Abstract

In the ONH, the MBR ratio increased significantly over the baseline after 2 min (104.8 ± 5.0%, p = 0.001) and 4 min (104.4 ± 5.6%, p = 0.005), in a supine position, but decreased to the initial level after only 6 min. In the choroid, on the other hand, while the MBR ratio also increased significantly after 2 min in a supine position (113.7 ± 8.1%, p < 0.001), it kept this significant increase over the time course of 10 min. After 10 min in a supine position, IOP increased significantly (p < 0.001), systolic blood pressure decreased significantly (p < 0.001), but diastolic blood pressure did not change significantly compared to the baseline. (p = 0.07) CONCLUSIONS: ONH and choroidal circulation have significantly different hemodynamics in response to posture change in healthy volunteers. This finding suggests that LSFG enables us to assess the autoregulation of BF in the ONH.