Measurement procedures in confocal choroidal laser Doppler flowmetry

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Physiology

Background:

• Confocal laser Doppler flowmetry is a key technique for measuring choroidal blood flow.
• Determining optimal measurement protocols is crucial for reliable and reproducible research outcomes.
• Adequate statistical power is essential for the validity of future clinical studies.

Purpose of the Study:

• To establish a practical number of measurements for confocal choroidal laser Doppler flowmetry.
• To ensure sufficient statistical power for future research investigating choroidal blood flow.
• To optimize data acquisition protocols for this specific technology.

Main Methods:

• Ten independent measurements of choroidal blood flow were taken within 30 minutes in 24 subjects.
• Subsequent series of measurements were recorded at 2 and 7 days post-baseline in 12 subjects.
• Choroidal blood flow parameters (velocity, volume, flux) were analyzed using varying numbers of measurements (3-10) from each series.

Main Results:

• Average values of choroidal blood flow parameters stabilized after 5-7 independent measurements.
• Six measurements provided approximately 80% statistical power for detecting a 15% difference between means.
• Baseline measurements exhibited higher values compared to subsequent recordings, highlighting the need for familiarization.

Conclusions:

• A familiarization session prior to experimental measurements is advisable.
• Utilizing an average of at least 6 measurements per series is recommended for robust data.
• These findings contribute to optimizing the methodology for choroidal blood flow assessment.