Retinal single-cell blood velocity in eyes with varied axial length using adaptive optics scanning laser ophthalmoscopy
摘要
To investigate the hemodynamic changes in the retinal vasculature of the macular region in eyes with axial myopia.
MethodsIndividuals with varying axial lengths were included in this study. Inclusion criteria was the absence of any ocular or systemic diseases. A commercial adaptive optics scanning laser ophthalmoscopy was used to capture images of retinal vessels within the 5°-10° areas above and below the foveal centre. This system provided noninvasive imaging of single blood cells and automatically calculated blood velocity while detecting the flow direction. Vessels were classified based on their diameter.
ResultsThe study included 90 patients (180 eyes; 35 (38.9%) men) with a mean age of 34.3 ± 12.2 years (range: 19-62 years) and a mean axial length of 25.8 ± 1.9 mm (range: 21.4–30.6 mm). The mean blood velocity in retinal arteries and veins was 35.2 ± 11.4 mm/s and 34.9 ± 13.2 mm/s, respectively. Single-cell blood velocity was significantly increased with longer axial length in large retinal arteries (diamater≥100μm) (B = 2.73; β = 0.32; P = 0.01); and medium retinal arteries (diameter<100μm) (B = 1.83; β = 0.27; P = 0.003). Correspondingly, the blood velocity of medium retinal arteries in the myopic group was significantly higher than that in the non-myopic group (t = 3.37; P = 0.001). Single-cell blood velocity was significantly increased with longer axial length in medium retinal veins (diameter <110 μm) (B = 2.0; β = 0.3; P = 0.016). Correspondingly, the blood velocity of medium retinal veins in the myopic group was significantly higher than that in the non-myopic group (t = 2.25; P = 0.03).
ConclusionsSingle-cell retinal blood velocity was significantly increased with longer axial length. These findings suggest that the hemodynamic changes observed in axial myopia, including higher arterial and venous blood velocities, may provide a potential explanation for the lower prevalence of diabetic retinopathy, age-related macular degeneration, and branch retinal vein occlusion reported in previous epidemiological studies.