Compact laser Doppler choroidal flowmeter

Area of Science:

• Ophthalmology
• Biomedical Optics
• Medical Instrumentation

Background:

• Accurate measurement of ocular blood flow is crucial for understanding and diagnosing various eye conditions.
• Existing methods for assessing foveal blood flow can be invasive or lack precision.

Purpose of the Study:

• To introduce and validate a novel compact instrument for measuring laser Doppler flow parameters in the human foveal choroidal vascular system.
• To assess the reproducibility and sensitivity of the new device for ocular blood flow measurements.

Main Methods:

• Development of a compact instrument utilizing confocality for laser light delivery and heterodyne detection.
• Measurement of blood velocity, volume, and flow in the foveal region of 21 normal volunteers using a 785 nm laser (90 μW incident power).
• Determination of intrasubject reproducibility and minimum detectable changes in flow parameters.

Main Results:

• The instrument successfully measured laser Doppler flow parameters (velocity, volume, flow) in the foveal region.
• High intrasubject reproducibility and statistically significant detectable changes in flow parameters were determined.
• Linear correlations between flow parameters in the right and left eyes were established.

Conclusions:

• The described compact instrument provides a non-invasive and reproducible method for assessing foveal choroidal blood flow.
• This technology holds potential for clinical applications in diagnosing and monitoring eye diseases related to blood flow abnormalities.