Abstract
Purpose. Image analysis by the retinal vessel analyzer (RVA) observes retinal
vessels in their dynamic state online noninvasively along a chosen vessel
segment. It has been found that high-frequency diameter changes in the retinal
artery blood column along the vessel increase significantly in anamnestically
healthy volunteers with increasing age and in patients with glaucoma during
vascular dilation. This study was undertaken to investigate whether longitudinal
sections of the retinal artery blood column are altered in systemic hypertension.
Methods. Retinal arteries of 15 untreated patients with essential arterial
hypertension (age, 50.9 +/- 11.9 years) and of 15 age-matched anamnestically
healthy volunteers were examined by RVA. After baseline assessment, a
monochromatic luminance flicker (530-600 nm; 12.5 Hz; 20 s) was applied to evoke
retinal vasodilation. Differences in amplitude and frequency of spatial artery
blood column diameter change along segments (longitudinal arterial profiles) of 1
mm in length were measured and analyzed using Fourier transformation. Results. In
the control group, average reduced power spectra (ARPS) of longitudinal arterial
profiles did not differ when arteries changed from constriction to dilation. In
the systemic hypertension group, ARPS during constriction, baseline, and
restoration were identical and differed from ARPS during dilation (P < 0.05).
Longitudinal arterial profiles in both groups showed significant dissimilitude at
baseline and restoration (P < 0.05). Conclusions. The retinal artery blood column
demonstrates microstructural alterations in systemic hypertension and is less
irregular along the vessel axis during vessel dilation. These microstructural
changes may be an indication of alterations in vessel wall rigidity, vascular
endothelial function, and smooth muscle cells in this disease, leading to
impaired perfusion and regulation.
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