Estimation of total vascular resistance, compliance, and arterial critical closing pressure of the retina from Doppler holography via external physiological pressure measurements

We present a non-invasive method to estimate total retinal vascular resistance, compliance, relaxation time, and arterial critical closing pressure by combining real-time Doppler holography with brachial and intraocular pressure measurements. Arterio–venous blood volume rate waveforms were acquired in primary retinal vessels and analyzed with the EyeFlow (v2.6.2) and HoloDoppler (v2.8) pipelines. Hemodynamic parameters were derived from volumetric flow variations and physiological pressure inputs, yielding values consistent with expected physiology (e.g., vascular resistance ≈ 0.57 mmHg·min/µL, compliance ≈ 1.97 nL/mmHg, CrCP ≈ 5.1 mmHg, relaxation time ≈ 105 ms). This approach enables reproducible, beat-to-beat characterization of retinal vascular mechanics, with potential applications in functional microvascular assessment in ophthalmology and cardiology.