Calculation of central retinal artery diameters in patients with type 1 diabetes using non‐invasive measurements

Abstract

AbstractPurpose To compare the diameter of the central retinal artery between patients with type 1 diabetes and healthy control subjects in vivo. Central retinal artery diameters were calculated from results of non‐invasive measurements of ocular hemodynamics.Methods 16 patients with type 1 diabetes with no or mild diabetic retinopathy and 16 age‐matched healthy controls were participated in this study. Total retinal blood flow was assessed by the use of laser Doppler velocimetry and measurement of retinal vessel diameters in all veins entering the optic disc using a Dynamic Vessel Analyzer. In addition blood flow velocity in the retrobulbar central retinal artery was measured using color Doppler imaging. The diameter of the central retinal artery was then calculated individually for each subject using the obtained ocular hemodynamic data.Results Calculated central retinal artery diameters were significantly larger in patients with diabetes (180 ± 13 µm) compared to healthy controls (166 ± 10 µm, p = 0.001). There were no significant differences in retinal blood flow, retinal vessel diameters or mean flow velocity in the central retinal artery between the two groups.Conclusion The present results indicate a dilation of the central retinal artery in patients with type 1 diabetes, whereas total retinal blood flow is unaltered compared to healthy controls. Results from blood flow velocity measurements using color Doppler imaging in retrobulbar vessels do not include information about vessel diameters and need to be interpreted with caution in terms of retinal blood flow.