Spontaneous oscillations in the diameter of retinal arterioles from normal persons decrease with age

Abstract

PurposeThe retinal vascular system is devoid of autonomic nervous supply, and consequently retinal blood flow is autoregulated. This includes pressure autoregulation, metabolic autoregulation and spontaneous oscillations in the diameter of retinal arterioles, so called vasomotion. It has been shown that vasomotion is impaired in diabetic patients, but it is unknown to what extent vasomotion results in retinal vascular disease should be corrected for age.MethodsForty‐eight normal persons consisting of at least 8 persons within each of the age groups (in years): 20–29, 30–39, 40–49, 50–59 and 60–69 were included. The patients had been examined by video recording of the retinal vessels using the Dynamic Vessel Analyzer, and diameter changes at five different locations on both arterioles and venules were analyzed by Fourier analysis. The power of the oscillations was calculated in five frequency bands defined as: (1) <0.04 Hz the very low frequency (VLF), (2) ≥0.04 and <0.15 Hz as the low frequency (LF), (3) ≥0.15 Hz and <0.4 Hz as high frequency (HF), (4) ≥0.4 and <2 Hz (VHF) normally containing the heart rate, and (5) 2‐12.5 Hz as a ultra high frequency (UHF).ResultsIn all arteriolar segments the power of spontaneous diameter oscillations with high frequencies showed a negative correlation with age, and the correlation was also found for low frequencies 1½ disk diameter from the optic disk (R2 = 0.0038 ± , p < 0.003 for all comparisons).ConclusionsPower analysis of spontaneous diameter changes in retinal arterioles should be corrected for age before results from different patient groups can be compared.