Purpose: To show that extending Doppler imaging into the high-frequency domain could allow detection and characterization of blood flow in small arterioles and capillaries.
Methods: A 40-MHz continuous wave Doppler system and a 60-MHz pulsed-wave Doppler system were constructed, tested, and used to examine the ciliary body region in two normal volunteers.
Results: Ciliary body circulation in the region of the great circle of the iris, which is undetectable by conventional 7.5-MHz duplex Doppler, was consistently and reproducibly detectable by high-frequency (40-MHz and 60-MHz) Doppler systems.
Conclusion: High-frequency Doppler imaging may provide a unique new tool for the characterization and assessment of anterior segment ocular blood flow.