Title
In vivo subdiffuse scanning laser oximetry of the human retina
Author
Damodaran, M.
Amelink, A.
Feroldi, F.
Lochocki, B.
Davidoiu, V.
de Boer, J.F.
Publication year
2019
Abstract
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.
Subject
High Tech Systems & Materials
Industrial Innovation
Retinal oximetry
Blood vessels
Hemoglobin oxygen saturation
Ophthalmology
Signal to noise ratio
Spectroscopy
Effective path lengths
Monochromatic lasers
Oximetry
Oxygen saturation
Relative intensity noise
Scanning laser ophthalmoscope
Superluminescent diode
Hyperspectral imaging
To reference this document use:
http://resolver.tudelft.nl/uuid:647f9ba0-e963-4b24-a6fe-2008ef3a68f8
DOI
https://doi.org/10.1117/1.jbo.24.9.096009
TNO identifier
869494
Publisher
SPIE
ISSN
1083-3668
Source
Journal of Biomedical Optics, 24 (9)
Article number
96009
Document type
article