Response to assessment of retinal vasculature in pregnancy : unveiling the complex pathogenesis of gestational vascular complications

Letter to the Editor: We thank Triantafyllou et al for the insightful questions they have raised about our article. Through adjusting the central retinal arteriolar equivalent and the central retinal venular equivalent for blood pressure (BP), we provide a single measurement with which to compare changes in the maternal peripheral cardiovascular system, particularly peripheral resistance. Because the diameter of an arteriole or venule is directly related to the pressure within the vessel, adjusting vessel diameter for BP generates data on peripheral resistance, which is easily comparable between individuals, groups, and in the same individual at different time points. We hypothesize that adjusting the retinal vascular diameter by BP allows a greater understanding of the dynamics of the physiology and pathology of the cardiovascular system than either of these values alone.1 Women with preeclampsia have been shown to have significantly higher impedance to blood flow in spiral arteries when compared with normotensive women,2 and our article expands these findings by showing reduced peripheral resistance in the retinal microvasculature of women with preeclampsia.