[Measuring choroid blood flow with a new confocal laser Doppler device].

UNLABELLED

A new instrument for the measurement of choroidal blood flow in the fovea is presented. It is based on the laser Doppler method and a confocal optical system with an indirect detection of the Doppler shifted light.

METHOD

The intensity of the laser beam (785 nm) at the cornea is 90 microW. Measurements were obtained from a normal population of 21 subjects under resting conditions without dilating the pupil.

RESULTS

The reproducibility of the choroidal blood flow, based on 5 measurements of 10 s each in 5 randomly selected subjects, is 9%. The minimum detectable change for a statistical significance of p < or = 0.05, based on a population of 21 subjects and 10 s measurements, is 9%.

CONCLUSION

This new compact instrument appears to be suitable for the investigation of the physiology and pharmacology of choroidal blood flow and the effect of age-related macular degeneration.