Retinal arteriolar imaging represents a promising method to assess microcirculation in humans. A recently developed non-invasive opto-electronic technology (Adaptive Optics Camera, AOC, RTX1® -ImagineEye,Orsay, France) provides a morphologic analysis of the retinal arteriolar tree, through the measurement of a novel remodeling index, the wall-to-lumen ratio (WLR). Our aim was to evaluate the effects of blood pressure (BP) drop on retinal arteriolar remodeling in newly diagnosed hypertensive patients in a short-term vs long-term follow-up.Design and Method:
57 hypertensive subjects without diabetes were consecutively enrolled and evaluated at baseline, 6 weeks (short-term) and 40 weeks (long-term). Among them, 28 had stable BP and 29 had BP drop after starting antihypertensive therapy after baseline visit. Wall Thickness (WT), Internal Diameter (ID), Wall Cross Sectional Area (WCSA) and WLR were measured with AOC.Results:
In the “BP drop” group, mean SBP/DBP, WT, ID, WLR and WCSA at baseline were 157/86 mmHg, 24.7 ± 4.7 μm, 73.3 ± 8.8 μm, 0.342 ± 0.07 and 3352 ± 943 μm2, respectively. At short and long-term follow up SBP decrease was – 13% and −21% and DBP −7 % and −12%, respectively. While WCSA remained stable at 6 weeks, a statistically significant reduction in WLR (−6%) was observed due to lumen dilatation (+2.4%) and wall thinning (−4%). After 40 weeks, while WCSA still remained stable, a further WLR decrease was observed compared to baseline (−11%) due to both further lumen dilatation (+5.6%) and arterial wall thickness decrease (−6.5%). No changes in BP or in retinal arteriole anatomical indices were observed in the “stable BP” group throughout.Conclusions:
After antihypertensive treatment induced BP drop, the observed WLR decrease is due to lumen dilatation and wall thinning without any significant WCSA change. This suggests that this retinal arteriole reverse eutrophic remodeling depends on changes in BP, myogenic tone and wall components rearrangements more than on wall mass changes.