Does internal longitudinal microstructure of retinal veins change with age in medically healthy persons

Purpose We demonstrated previously that roughness of the retinal arterial blood column measured along the vessel axis, termed longitudinal arterial profile (LAP) increases significantly in anamnesticly healthy volunteers with increasing age. Recently we have demonstrated age related changes in LAP of medically healthy persons. Whether longitudinal retinal venous profiles (LVP) are altered with age in this group is investigated. Methods 83 medically healthy volunteers were examined by Dynamic Vessel Analyzer (IMEDOS, Jena, Germany) using stimulation with flickering light. 3 age groups were formed: young (N=28, 30,2±4,3 years), middle age (N=28, 42,3±3,3 years) and seniors (N=27, 64,0±5,0 years). Included in the analysis were volunteers without medical vascular risk factors defined as: blood pressure 35 mg/dl, LDL < 190 mg/dl and glucose levels < 110 mg/dl. Retinal venous diameters were measured along 1 mm vessel segments to obtain LVP. Differences were analyzed using Fourier transformation. Results In all age groups power spectra of LVP do not change during all stages of the venous response to the stimulation. There were no significant differences in LVP between the age groups. Venous diameters in middle-age group were reduced in comparison to the young group at all stages of vessel reaction (p<0,05). Conclusion Our results indicate that in contrast to retinal arteries retinal veins of validated healthy volunteers do not undergo age related microstructural changes. Hence previously reported age related decrease of retinal venous diameter might have physiologic origin due to reduced blood flow in retinal microcirculation with age, not because of structural changes of venous wall.