Purchase this article with an account.
Yukihiro Shiga, Yu Yokoyama, Nahoko Aizawa, Naoki Chiba, Satoru Tsuda, Toru Nakazawa; Evaluation Of Retinal Circulation Using Laser Speckle Flowgraphy After Postural Change. Invest. Ophthalmol. Vis. Sci. 2011;52(14):6034.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the autoregulation of retinal blood flow in response to the postural change using Laser Speckle Flowgraphy.
Eleven healthy volunteers without systemic symptoms of vascular dysregulation (age: 35±8, 11 eyes, male:female=7:4) were included in this study. The retinal circulation on the left eye was accessed by the mean bluer rates (MBRs) of laser speckle flowgraphy (LSFG) on sitting and supine position (every 2 minutes till 8 minutes). MBRs at the optic disc or the choroid during sitting position were regarded as the baseline and the increased ratio of MBRs on the supine position was calculated. Intraocular pressure (IOP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were also recorded. The ocular perfusion pressure (OPP) was calculated as OPP = 2/3[1/3SBP + 2/3DBP] - IOP. These parameters were compared to the baseline with Wilcoxon signed-rank test and the statistical significance was set at P<0.05.
In the optic disc, the MBRs of supine position were significantly increased at 2 min (106 %, P=0.03), 4 min (105%, P=0.02), and 6 min (104%, P =0.02) compared to the MBRs of sitting position, but not in 8 min (102%, P=0.08). On the other hand, in choroid, MBRs of supine position were significantly increased at 2 min (112%, P=0.008), 4 min (109%, P=0.02), 6 min (112%, P=0.02), and 8 min (109%, P =0.04) compared to the MBRs of sitting position. Average blood pressure (P=0.17) and IOP (P=0.07) were not significantly different at every time point on the supine position. The OPP at final measuring point on the supine position (41.8mmHg) was significantly more decreased than that on the sitting position (46.6 mmHg, P=0.02).
Optic nerve and choroidal circulation have different hemodynamics in response to postural change. This finding suggests that LSFG enable us to access the autoreguration of optic nerve blood flow.
This PDF is available to Subscribers Only