TY - JOUR
T1 - In vivo subdiffuse scanning laser oximetry of the human retina
AU - Damodaran, Mathi
AU - Amelink, Arjen
AU - Feroldi, Fabio
AU - Lochocki, Benjamin
AU - Davidoiu, Valentina
AU - de Boer, Johannes F.
PY - 2019/9/1
Y1 - 2019/9/1
N2 - Scanning laser ophthalmoscopes (SLOs) have the potential to perform high speed, high contrast, functional imaging of the human retina for diagnosis and follow-up of retinal diseases. Commercial SLOs typically use a monochromatic laser source or a superluminescent diode for imaging. Multispectral SLOs using an array of laser sources for spectral imaging have been demonstrated in research settings, with applications mainly aiming at retinal oxygenation measurements. Previous SLO-based oximetry techniques are predominantly based on wavelengths that depend on laser source availability. We describe an SLO system based on a supercontinuum (SC) source and a double-clad fiber using the single-mode core for illumination and the larger inner cladding for quasi-confocal detection to increase throughput and signal-to-noise ratio. A balanced detection scheme was implemented to suppress the relative intensity noise of the SC source. The SLO produced dual wavelength, high-quality images at 10 frames / s with a maximum 20 deg imaging field-of-view with any desired combination of wavelengths in the visible spectrum. We demonstrate SLO-based dual-wavelength oximetry in vessels down to 50 μm in diameter. Reproducibility was demonstrated by performing three different imaging sessions of the same volunteer, 8 min apart. Finally, by performing a wavelength sweep between 485 and 608 nm, we determined, for our SLO geometry, an approximately linear relationship between the effective path length of photons through the blood vessels and the vessel diameter..
AB - Scanning laser ophthalmoscopes (SLOs) have the potential to perform high speed, high contrast, functional imaging of the human retina for diagnosis and follow-up of retinal diseases. Commercial SLOs typically use a monochromatic laser source or a superluminescent diode for imaging. Multispectral SLOs using an array of laser sources for spectral imaging have been demonstrated in research settings, with applications mainly aiming at retinal oxygenation measurements. Previous SLO-based oximetry techniques are predominantly based on wavelengths that depend on laser source availability. We describe an SLO system based on a supercontinuum (SC) source and a double-clad fiber using the single-mode core for illumination and the larger inner cladding for quasi-confocal detection to increase throughput and signal-to-noise ratio. A balanced detection scheme was implemented to suppress the relative intensity noise of the SC source. The SLO produced dual wavelength, high-quality images at 10 frames / s with a maximum 20 deg imaging field-of-view with any desired combination of wavelengths in the visible spectrum. We demonstrate SLO-based dual-wavelength oximetry in vessels down to 50 μm in diameter. Reproducibility was demonstrated by performing three different imaging sessions of the same volunteer, 8 min apart. Finally, by performing a wavelength sweep between 485 and 608 nm, we determined, for our SLO geometry, an approximately linear relationship between the effective path length of photons through the blood vessels and the vessel diameter..
KW - hemoglobin
KW - hyperspectral imaging
KW - oxygen saturation
KW - path length
KW - retinal oximetry
KW - scanning laser ophthalmoscope
UR - http://www.scopus.com/inward/record.url?scp=85072770863&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85072770863&partnerID=8YFLogxK
UR - https://www.mendeley.com/catalogue/vivo-subdiffuse-scanning-laser-oximetry-human-retina/
U2 - https://doi.org/10.1117/1.JBO.24.9.096009
DO - https://doi.org/10.1117/1.JBO.24.9.096009
M3 - Article
C2 - 31571433
SN - 1083-3668
VL - 24
SP - 1
EP - 14
JO - Journal of biomedical optics
JF - Journal of biomedical optics
IS - 9
M1 - 096009
ER -