Abstract
Purpose :
Increased retinal blood flow (RBF) in response to flicker stimulation is an indicator of retinal-neurovascular coupling, which is the interaction of the functional complex of retinal neurion, retinal glia, and RBF. We investigated the RBF response in healthy individuals using the continuous measurement function of laser speckle flowgraphy (LSFG), a widely used blood flow device in clinical practice.
Methods :
Ocular perfusion pressure (OPP) and resting RBF were measured using LSFG in 20 healthy adults (9 males and 11 females) without underlying diseases. In addition, the RBF was measured every 5 s during 1 min flicker stimulation and plotted over time as a percentage of the change from the resting RBF. The analysis items were MA(Mean of All area), MV(Mean of Vascular area), MT(Mean of Tissue area), which indicate the relative MBR(Mean Blur Rate) of blood flow.
Results :
The mean age of the participants was 44.4 ± 17.1 years and the OPP was 45.2 ± 7.2 mmHg. The resting RBF flows were MA: 20.8 ± 5.2, MV: 42.8 ± 10.9, and MT: 11.9 ± 3.0 (a.u.). The maximum percent changes in RBF with flicker stimulation were MA: 31.0% ± 19.0% (time to peak: 35.5 ± 16.8 s), MV: 26.2% ± 26.0% (time to peak: 35.3 ± 14.8 s), and MT: 39.7% ± 34.6% (time to peak: 34.3 ± 18.1s). In addition, these responses returned to the resting RBF within 1 min after the end of stimulation. The areas under the curve of blood flow response during the stimulation period were MA: 190.0 ± 108.8, MV: 156.1 ± 118.3, and MT: 228.8 ± 145.4 (a.u.), and these values did not correlate with either age, OPP or resting RBF.
Conclusions :
We successfully captured the response of healthy participants to increased RBF induced by flicker stimulation using the LSFG serial measurement method.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.