A comparison of colour Doppler imaging of orbital vessels and other methods of blood flow assessment

Background: Comparison of the haemodynamic measurements obtained by colour Doppler imaging and other methods of ocular blood flow measurements was desired. Methods: The blood velocity findings from colour Doppler imaging of patients with central retinal vein occlusion were compared to the results of fluorescein video-angiography, continuous tonography and ophthalmodynamometry. Results: Patients with low or undetectable blood velocities in the central retinal vein had longer retinal dye transit times on fluorescein video-angiography. Tonography showed a positive correlation with the velocities in the ophthalmic artery, but ophthalmo-dynamometry showed a negative correlation with these velocities. Conclusion: The relationships between the blood velocities in orbital vessels and other blood flow measurements emphasise that there is a complex interaction of the blood flow parameters. Care must therefore be taken when interpreting the results of studies.