Pulsatile haemodynamics: potential for end‐organ damage?

Abstract

Abstract Purpose Increases in velocity pulse wave amplitude, or max:min velocity ratio, represent early haemodynamic disturbances associated with diabetic retinopathy (DR) and age‐related macular degeneration. This change reflects an increase in vessel wall rigidity that is generally accepted to occur in the central vasculature but the peripheral vasculature is also implicated in this process. This presentation will highlight the implications of these changes in terms of end‐organ damage in DR. Methods The sample comprised 4 groups: Group 1: 50 non‐diabetic control subjects. Group 2: 56 diabetic patients without clinically visible DR. Group 3: 54 diabetic patients with micro‐aneurysms and / or hard exudates within 2 disc diameters of the fovea in the absence of clinically manifest diabetic macular edema (DME). Group 4: 40 patients with clinically manifest DME. The diabetic patients were predominantly type 2. Retinal hemodynamics were assessed in the superior temporal retinal arteriole using the Canon Laser Blood Flowmeter. Intraocular pressure, blood pressure and relevant systemic markers of diabetes control and complications were also assessed. Results The velocity pulse wave amplitude was elevated with increasing risk of DME (p<0.0001). No significant differences were found between the groups with respect to diameter, velocity or flow. Pulse wave amplitude was correlated to age, duration of diabetes, blood pressure, pulse rate, IOP and serum potassium levels. Conclusion The increase in velocity pulse wave amplitude will induce excessive pressure pulsatility in the retinal arterioles and capillaries, changes in vascular function (e.g. loss of vascular regulation) and changes in vessel structure. Commercial interest