Abstract
Purpose:
Morphological changes affecting small retinal arteries are a surrogate of end-organ damage. Fine details of microvascular morphometry can be observed I the retina using adaptive optics (AO) near infrared (NIR) imaging (Koch et al, J Hypertens. in press). Here we investigated the changes of the diameter of retinal arterioles (50-150 μm diameter) in hypertensive humans after initiation of hypotensive treatment.
Methods:
In a group of hypertensive subjects (n = 9; mean 52.33 years [range, 42;66] mean systolic pressure 137.2 [range, 111;177]) the inner diameter (ID) of the superotemporal artery was measured by OA imaging (rtx1; ImagineEyes, France) using a custom software. The changes in ID before and after initiation of hypotensive treatment (calcium channel blocker, beta blocker, angiotensin receptor antagonist) were analyzed.
Results:
The mean follow-up was125 days [range, 48-258]. The ID showed a nonsignificant increase after initiation of hypotensive treatment patients although the observed effect varied greatly between subjects (average increase 3.4%; range, -0.5% to 10.9%). Blood pressure variations or treatment type were not correlated to variations of ID.
Conclusions:
The vasodilatory effect of hypotensive drugs can be measured in vivo using AO imaging. Hypotensive treatment induces variable changes in the diameter of small retinal arteries. The absence of correlation with blood pressure changes suggest that microvascular responses are independant biomakers of the effect of vasodilatory treatment and hence may be a parameter of interest for evaluating the risk of end-organ damage. Future studies on larger cohorts are ongoing.
Keywords: 550 imaging/image analysis: clinical •
503 drug toxicity/drug effects •
688 retina