Microstructure of the inner wall of retinal arteries change with age in anamnesticly healthy persons

Arteriosclerosis involves the whole human vascular system with a somewhat patchy appearance. Although typical arteriosclerotic lesions are confined to major arteries, vessels of microcirculation are affected as well. Retinal vessels are part of the microvascular bed. They can be assessed in non invasive ways by rather simple optical methods and are similar to cerebral vessels in their structure and function. Retinal vessels are not straight tubes with a constant lumen, but rather possess narrower and wider diameters in different segments. The aim of the present work was to study functional and morphological age-related alterations in retinal vasculature as well as to determine quantitative parameters which could characterize these changes. Changes in longitudinal vessel section of retinal arterial segments were examined clinically by Retinal Vessel Analyzer (IMEDOS, Germany) in 35 anamnesticaly healthy persons at the age of 21—27 years, 40—60 years and 60—85. A monochromatic flicker of 12.5 Hz was applied for 60 s. Arterial diameters were measured in vessel segments of 1 mm in length in order to obtain the longitudinal arterial profiles. Differences in amplitude and frequency of arterial widths change were characterized by the parameter ‘spectral edge frequency’ (SEF). The rate of microirregularity of retinal arterial inner walls along a vessel increased significantly in anamnesticaly healthy volunteers with increasing age. SEF was significantly different between the young and senior age groups in each phase of the arterial reaction to flicker ( p < 0,05, Mann-Whitney-Test). No significant difference within any age group was found in each phase of the arterial reaction. No significant difference between the middle age and either young or old volunteers was found at baseline. However following stimulation the middle age group displayed a significant difference to the young group with values resembling the old age group. It is concluded, that retinal arteries in the elderly sustain significant microstructural changes of their longitudinal profiles, which might be of either functional or irreversible nature and might be an expression of endothelial damage, the instability of vessel wall or partial degradation of smooth musculature of vessel wall.