KEYWORDS: Eye, Hemodynamics, Retina, Imaging systems, In vivo imaging, Cameras, Optical coherence tomography, Signal to noise ratio, Neurophotonics, Tunable filters
SignificanceMicrocirculation and neurovascular coupling are important parameters to study in neurological and neuro-ophthalmic conditions. As the retina shares many similarities with the cerebral cortex and is optically accessible, a special focus is directed to assessing the chorioretinal structure, microvasculature, and hemodynamics of mice, a vital animal model for vision and neuroscience research.AimWe aim to introduce an optical imaging tool enabling in vivo volumetric mouse retinal monitoring of vascular hemodynamics with high temporal resolution.ApproachWe translated the spatio-temporal optical coherence tomography (STOC-T) technique into the field of small animal imaging by designing a new optical system that could compensate for the mouse eye refractive error. We also developed post-processing algorithms, notably for the assessment of (i) localized hemodynamics from the analysis of pulse wave–induced Doppler artifact modulation and (ii) retinal tissue displacement from phase-sensitive measurements.ResultsWe acquired high-quality, in vivo volumetric mouse retina images at a rate of 113 Hz over a lateral field of view of ∼500 μm. We presented high-resolution en face images of the retinal and choroidal structure and microvasculature from various layers, after digital aberration correction. We were able to measure the pulse wave velocity in capillaries of the outer plexiform layer with a mean speed of 0.35 mm/s and identified venous and arterial pulsation frequency and phase delay. We quantified the modulation amplitudes of tissue displacement near major vessels (with peaks of 150 nm), potentially carrying information about the biomechanical properties of the retinal layers involved. Last, we identified the delays between retinal displacements due to the passing of venous and arterial pulse waves.ConclusionsThe developed STOC-T system provides insights into the hemodynamics of the mouse retina and choroid that could be beneficial in the study of neurovascular coupling and vasculature and flow speed anomalies in neurological and neuro-ophthalmic conditions.
We present a novel ultrafast imaging system using Spatio-Temporal Optical Coherence Tomography (STOC-T), capable of acquiring structural images of a mouse retina at a volumetric rate of 112 Hz, aided by a calibrated fundus camera for focal plane adjustment. We extract blood pulse traces from retinal and choroidal vessels using a structural-only OCT analysis, and pulse wave-induced retinal layer displacement from differential OCT phase analysis. With both analyses, we measure hemodynamic parameters, such as the delays between arterial and venous pulsation, to provide a comprehensive suite of potential biomarkers of retinal diseases.
We present a novel ultrafast imaging system using Spatio-Temporal Optical Coherence Tomography (STOC-T), capable of acquiring structural images of a mouse retina at a volumetric rate of 112 Hz. A calibrated fundus camera and white-light illumination aid the alignment of the mouse and the adjustment of the focal plane in the mouse retina for the STOC-T image. We extract pulsatile blood flow frequency and other hemodynamic parameters from multiple retinal and choroidal vessels from structural-only OCT images, highlighting the prospects of STOC-T for monitoring retinal hemodynamics in a simple way.
We present a novel mouse eye imaging system based on the Spatio-Temporal Optical Coherence Tomography (STOC-T) technique capable of acquiring structural image of a mouse retina at a volumetric rate of 112 Hz. A fundus camera and white light illumination aid the alignment of the mouse and the adjustment of the focal plane in the mouse retina for the STOC-T image. The fundus camera is calibrated so that when the white-light image of the mouse eye fundus appears in focus after the appropriate gel thickness is selected for a given mouse and bi-concave lens, the corresponding near infrared STOC-T image of the photoreceptor layer is also in focus, albeit with minor shifts. We present images of retinal and choroidal tissue from a B6 albino wild type mouse after the focal plane adjustment with richness of details.
We report on a novel mice imaging system based on the Spatio-Temporal Optical Coherence Tomography (STOC-T)
technique. The contribution describes the translation of the STOC-T technique, initially developed for human eye imaging, into the field of experimental small animal imaging. We present images of retinal and choroidal tissue from a B6 albino wild type mouse acquired at a volumetric rate of 112 Hz.
Correlation methods were used to characterize the activity of single neurons and network connections in three
subcortical structures of the cat visual system. Autocorrelation analysis performed on spike trains of single cells recorded
from the lateral geniculate and perigeniculate nuclei showed the presence of bursts of high-frequency oscillations
ranging from 100 to 550 Hz in their spontaneous activity. Autocorrelation performed on spike trains of single cells
recorded from the superior colliculus also revealed oscillations, but in the frequency range of 10 - 90 Hz, both in the
spontaneous and visually evoked neuronal activity. The presence of oscillations was confirmed with spectral analysis
and a shift predictor was used to distinguish between stimulus-locked and stimulus-independent oscillations in visually
evoked activities. Additionally, a crosscorrelation analysis performed on two spike trains recorded from the same
electrode or pairs of electrodes in the superior colliculus, revealed a common input from an external source and the
presence of inhibitory interactions in the neuronal network.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.