Imaging of retinal vasculature using adaptive optics SLO/OCT

Felberer, Franz; Rechenmacher, Matthias; Haindl, Richard; Baumann, Bernhard; Hitzenberger, Christoph K.; Pircher, Michael

doi:10.1364/boe.6.001407

Cited by 33 publications

(27 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Further exploration of these effects in humans would require measurement of diameters in smaller arterioles and venules as well as capillaries, which may be possible only by adaptive optics technology. [47][48][49] To give an example for the alterations of flow conditions in one subject, the flow was plotted over the diameter in a log-log plot for all vessels of subject 6 at baseline conditions (Fig. 9a) and during stimulation with diffuse luminance flicker (Fig.…”

Section: Discussionmentioning

confidence: 99%

Effect of Diffuse Luminance Flicker Light Stimulation on Total Retinal Blood Flow Assessed With Dual-Beam Bidirectional Doppler OCT

Aschinger

Schmetterer

Fondi

et al. 2017

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

METHODS. In six healthy subjects, TRBF was measured before and during stimulation with diffuse luminance flicker. Blood flow velocities in retinal vessels were measured via dual-beam bidirectional Doppler Fourier-domain optical coherence tomography (FD-OCT), retinal vessel diameters were assessed based on FD-OCT phase data. This allowed for the calculation of TRBF before and during visual stimulation. Additionally, a mathematical flow model for the retinal vasculature was adapted to study the implications of diameter variations on retinal perfusion. Measured and simulated perfusion was compared to draw conclusions on the diameter variations in different layers of the vascular tree.RESULTS. The measured mean baseline flow was 36.4 6 6.5 ll/min while the mean flow during flicker stimulation was 53.4% 6 8.3 ll/min. The individual increase in TRBF during flicker stimulation ranged between 34% and 66%. The average increase in TRBF over all measured subjects was 47.6% 6 12.6%.CONCLUSIONS. Dual-beam bidirectional Doppler FD-OCT allowed quantifying NC in the human retina in vivo and may be a promising method for monitoring alterations in NC caused by various pathologies. The comparison of the measured data with the results obtained in the simulated vasculature indicates that the vasodilation induced by NC is more pronounced in smaller vessels.

show abstract

Section: Discussionmentioning

confidence: 99%

Effect of Diffuse Luminance Flicker Light Stimulation on Total Retinal Blood Flow Assessed With Dual-Beam Bidirectional Doppler OCT

Aschinger

Schmetterer

Fondi

et al. 2017

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

show abstract

“…Similar strategies using Optical Coherence Tomography (OCT) combined with adaptive optics scanning ophthalmoscopy has also shown utility to visualize the retinal vasculature and obtain velocity measurements in arterioles and venules using 1D line scan [65,66]. OCT angiography has provided a transformative tool to map vascular perfusion at the structural and qualitative functional level [67].…”

Section: Comparison To Other Measurements Of Blood Flow and Velocitymentioning

confidence: 99%

Label free measurement of retinal blood cell flux, velocity, hematocrit and capillary width in the living mouse eye

Guevara–Torres

Joseph

Schallek

2016

Biomed. Opt. Express

135

View full text Add to dashboard Cite

Measuring blood cell dynamics within the capillaries of the living eye provides crucial information regarding the health of the microvascular network. To date, the study of single blood cell movement in this network has been obscured by optical aberrations, hindered by weak optical contrast, and often required injection of exogenous fluorescent dyes to perform measurements. Here we present a new strategy to non-invasively image single blood cells in the living mouse eye without contrast agents. Eye aberrations were corrected with an adaptive optics camera coupled with a fast, 15 kHz scanned beam orthogonal to a capillary of interest. Blood cells were imaged as they flowed past a near infrared imaging beam to which the eye is relatively insensitive. Optical contrast of cells was optimized using differential scatter of blood cells in the split-detector imaging configuration. Combined, these strategies provide label-free, non-invasive imaging of blood cells in the retina as they travel in single file in capillaries, enabling determination of cell flux, morphology, class, velocity, and rheology at the single cell level.

show abstract

“…In this case, aided by axial eye tracking, this device acquires volumes with high lateral and axial resolution and provided high resolution images of the photoreceptor mosaic. These systems are also useful for imaging the retinal vasculature, allowing for high resolution imaging of vessel walls and structures that may correspond to individual erythrocytes (Felberer et al, 2015). …”

Section: Multimodal Imaging: Combining Ao-oct With Other Modalitiesmentioning

confidence: 99%

Adaptive optics optical coherence tomography in glaucoma

Dong

Wollstein

Wang

et al. 2017

Progress in Retinal and Eye Research

View full text Add to dashboard Cite

Since the introduction of commercial optical coherence tomography (OCT) systems, the ophthalmic imaging modality has rapidly expanded and it has since changed the paradigm of visualization of the retina and revolutionized the management and diagnosis of neuro-retinal diseases, including glaucoma. OCT remains a dynamic and evolving imaging modality, growing from time-domain OCT to the improved spectral-domain OCT, adapting novel image analysis and processing methods, and onto the newer swept-source OCT and the implementation of adaptive optics (AO) into OCT. The incorporation of AO into ophthalmic imaging modalities has enhanced OCT by improving image resolution and quality, particularly in the posterior segment of the eye. Although OCT previously captured in-vivo cross-sectional images with unparalleled high resolution in the axial direction, monochromatic aberrations of the eye limit transverse or lateral resolution to about 15-20 μm and reduce overall image quality. In pairing AO technology with OCT, it is now possible to obtain diffraction-limited resolution images of the optic nerve head and retina in three-dimensions, increasing resolution down to a theoretical 3 μm3. It is now possible to visualize discrete structures within the posterior eye, such as photoreceptors, retinal nerve fiber layer bundles, the lamina cribrosa, and other structures relevant to glaucoma. Despite its limitations and barriers to widespread commercialization, the expanding role of AO in OCT is propelling this technology into clinical trials and onto becoming an invaluable modality in the clinician's arsenal.

show abstract

Imaging of retinal vasculature using adaptive optics SLO/OCT

Cited by 33 publications

References 56 publications

Effect of Diffuse Luminance Flicker Light Stimulation on Total Retinal Blood Flow Assessed With Dual-Beam Bidirectional Doppler OCT

Effect of Diffuse Luminance Flicker Light Stimulation on Total Retinal Blood Flow Assessed With Dual-Beam Bidirectional Doppler OCT

Label free measurement of retinal blood cell flux, velocity, hematocrit and capillary width in the living mouse eye

Adaptive optics optical coherence tomography in glaucoma

Contact Info

Product

Resources

About