Repeatability and reliability of retinal arterial hemodynamics measurement using Doppler holography

Reliable quantification of retinal arterial blood flow is important for diagnosing and monitoring ocular and systemic diseases. Existing techniques are limited by invasiveness, motion artifacts, or a lack of quantitative flow estimation.

The aim is to assess the repeatability, reproducibility, and robustness of laser Doppler holography (LDH) for measuring retinal arterial hemodynamics.

We acquired LDH data at 67 kHz in healthy volunteers (14 eyes intra-day and 4 eyes inter-day) and quantified blood volume rate, resistivity index (RI), and vessel diameter. Additional measurements evaluated sensitivity to axial displacement and gaze lateral positioning.

LDH successfully measured retinal arterial blood volume rate in all eyes, with a coefficient of variation (CoV) of 18.5% for the mean arterial blood volume rate and a CoV of 11% for RI. Inter-day reproducibility remained acceptable ( $\mathrm{CoV}\approx 20\%$ ). The mean arterial diameter estimation showed a CoV of $<3\%$ . Moderate axial or lateral shifts introduced small changes in hemodynamic values ( $<15\%$ CoV) compared with inter- or intra-day tests.

LDH provides reliable and robust measurements of retinal arterial hemodynamics and maintains performance under typical imaging variations (axial or gaze position). These findings support its potential for longitudinal studies and future clinical translation.