Background
The present study investigates the regulative retinal vascular answer to flicker as measured by Dynamic Vessel Analysis (DVA) in relation to age.
Material and Method
52 clinically healthy volunteers (age 20-78 years) free of cardiovascular risk factors according to an extensive medical history, lab values and blood pressure (BP) were examined by retinal DVA. The regulative arterial and venous responses to flicker were recorded with a Retinal Vessel Analyzer (Imedos, Jena/Germany).
Results
The retinal arterial regulative amplitude, consisting of a dilation and constriction component, diminished by 45% with age, mainly due to the constricting component diminishing by 75%. The venous response to flicker was unaltered.
Conclusions
The vascular regulative amplitude as well as its constriction part are observable in retinal arteries. They undergo major reduction in healthy individuals during adult lifetime. The results can be explained by the change of biomechanical properties of the vessel wall as well as physiological changes of the vascular endothelial function with age. Hereby the DVA technique shows good potential for investigating cardiovascular aspects in preventive medicine. Whenever doing functional DVA testing these results should be taken in account. The data obtained are first normative age related DVA data.

Keywords: Regression Analysis, Retinal Artery, Microvessels - physiology, Hematology - methods, Health, Retinal Vein, Aging - physiology, Retinal Vessels - physiology, young adult