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Laser Speckle Flowgraphy in Caucasians: Age Dependence and Comparison With Doppler Optical Coherence Tomography

NCT02582411 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 80

Last updated 2016-02-25

No results posted yet for this study

Summary

Some of the most prevalent eye diseases such as age-related macular degeneration, glaucoma and diabetic retinopathy are associated with ocular perfusion abnormalities. Currently, there is no gold-standard method for the measurement of ocular blood flow available. Laser speckle flowgraphy is a promising technique for the two-dimensional assessment of ocular blood flow in humans. So far the technique has, however, been only gained widespread use in Japan. The experience in Caucasian subjects is very limited. In a Japanese population it was shown that mean blur rate, a measure of chorioretinal blood velocity, decreases with age. This is of relevance, because an age-related decline in ocular blood flow may partially explain the age-dependence of ocular vascular disease. The present study investigates this age-dependence in healthy subjects. In addition, the investigators investigate in a sub-group of this population whether relative flow volume (RFV), a novel index of blood flow in the human retina derived from laser speckle flowgraphy is associated with retinal blood flow as assessed with bi-directional Doppler Optical Coherence Tomography (DOCT).

Conditions

  • Healthy

Interventions

DEVICE

Laser Speckle Flowgraphy

A commercially available LSFG (Softcare, Fukutsu, Japan) system will be used in the present study. The LSFG device consists of a fundus camera equipped with a diode laser with a wavelength if 830 nm and charge-coupled device. NB, the relative velocity of blood flow, is derived from the pattern of speckle contrast produced by the interference of a laser scattered by blood cells moving in the ocular fundus. Images are acquired continuously at the rate of 30 frames per seconds in a 4-second time period and stored on a personal computer. Heartbeat map of the optic nerve head and the retina/choroid is generated

DEVICE

Doppler Optical Coherence Tomography

A dual-beam bidirectional Doppler OCT system comprises a broadband superluminescent diode (SLD) with a central wavelength of 840 (spectral bandwidth 54 nm) and two CCD cameras with a maximum readout rate of 20 kHz. The system provides a resolution (in tissue) of about 6 and 18 μm in axial and lateral direction, respectively. The sample, i.e. the retinal vessel under study, is illuminated by two probe beams separated by their polarization properties. Light back scattered and backreflected from the sample is spectrally detected by two identical spectrometers and postprocessing, i.e. calculation the phase shift due moving scatterers within the sample, is carried out by a personal computer with software written in National Instruments LabView. The power of both probe beams incident on the cornea is 650 μW, which is below the ANSI (American National Standard Institute) limits for small source ocular exposure to a laser beam within the measuring time.

Sponsors & Collaborators

  • Medical University of Vienna

    lead OTHER

Eligibility

Min Age
18 Years
Max Age
80 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2015-08-31
Primary Completion
2016-01-31

Countries

  • Austria

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT02582411 on ClinicalTrials.gov