The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Nagahisa Yoshimura - One of the best experts on this subject based on the ideXlab platform.
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circinate partition like findings on cone mosaic imaged by adaptive optics Scanning Laser Ophthalmoscopy in eyes with inner nuclear layer microcystic changes
Retinal Cases & Brief Reports, 2017Co-Authors: Tomoko Hasegawa, Yukiko Makiyama, Kazuaki Miyamoto, Masayuki Hata, Sotaro Ooto, Nagahisa YoshimuraAbstract:PURPOSE To report cases that showed partition-like, dark areas in the cone mosaic on adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO) images in eyes with inner nuclear layer (INL) microcystic changes. METHODS Eyes with INL microcystic changes were imaged by prototype AO-SLO. RESULTS An eye with Leber hereditary optic neuropathy, an eye with traumatic optic neuropathy, and an eye with retinitis pigmentosa that showed microcystic lesions in the INL were imaged by AO-SLO. The images revealed characteristic, dark, partition-like lesions in the cone mosaic of all the eyes in areas where microcystic changes in the INL were shown by spectral domain optical coherence tomography. The AO-SLO findings in eyes with optic neuropathy were quite similar in shape and size to those seen in eyes with retinitis pigmentosa. CONCLUSION We report cases that manifest dark, partition-like areas in the cone mosaic on AO-SLO images. Microcystic lesions in the INL may affect the images of the cone mosaic.
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effects of age and blood pressure on the retinal arterial wall analyzed using adaptive optics Scanning Laser Ophthalmoscopy
Scientific Reports, 2015Co-Authors: Shigeta Arichika, Akihito Uji, Sotaro Ooto, Yuki Muraoka, Nagahisa YoshimuraAbstract:The wall-to-lumen ratio (WLR) of the vasculature is a promising early marker of retinal microvascular changes. Recently, adaptive optics Scanning Laser Ophthalmoscopy (AOSLO) enabled direct and noninvasive visualization of the arterial wall. Using AOSLO, we analyzed the correlation between age and WLR in 51 normal subjects. In addition, correlations between blood pressure and WLR were analyzed in 73 subjects (51 normal subjects and 22 hypertensive patients). WLR showed a strong correlation with age (r = 0.68, P < 0.0001), while outer diameter and inner diameter did not show significant correlation with age in the normal group (r = 0.13, P = 0.36 and r = −0.12, P = 0.41, respectively). In the normal and hypertensive groups, WLR showed a strong correlation with systolic and diastolic blood pressure (r = 0.60, P < 0.0001 and r = 0.65, P < 0.0001, respectively). In conclusion, AOSLO provided noninvasive and reproducible arterial measurements. WLR is an early marker of morphological changes in the retinal arteries due to age and blood pressure.
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retinal hemorheologic characterization of early stage diabetic retinopathy using adaptive optics Scanning Laser Ophthalmoscopy
Investigative Ophthalmology & Visual Science, 2014Co-Authors: Shigeta Arichika, Kazuaki Miyamoto, Sotaro Ooto, Akihito Uji, Tomoaki Murakami, Noriyuki Unoki, Shin Yoshitake, Yoko Dodo, Nagahisa YoshimuraAbstract:PURPOSE Adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO) is a noninvasive technique that allows for the direct monitoring of erythrocyte aggregates in retinal capillaries. We analyzed the retinal hemorheologic characteristics in normal subjects, diabetic patients without diabetic retinopathy (NDR), and diabetic patients with nonproliferative diabetic retinopathy (NPDR), using spatiotemporal (ST) blood flow images to visualize blood corpuscle trajectory. METHODS AO-SLO images of the parafoveal capillary network were acquired for three groups: 20 healthy volunteers, 17 diabetic patients with NDR (8 type 1 and 9 type 2 patients), and 10 diabetic patients with NPDR (4 type 1 and 6 type 2). The erythrocyte aggregate velocity assigned to a relative cardiac cycle and the elongation rate of the erythrocyte aggregate were calculated. RESULTS Careful observation revealed that flow velocity fluctuations were found with higher frequency in diabetic patients than in normal subjects. The total average velocities were 1.26 ± 0.22 mm/s in the normal group, 1.31 ± 0.21 mm/s in the NDR group, and 1.63 ± 0.35 mm/s in the NPDR group. The average velocities of the NPDR group were higher than those in the normal (P = 0.001) and NDR (P = 0.009) groups. The average elongation rates of the 3 groups were 0.67 ± 0.20, 0.39 ± 0.19, and 0.33 ± 0.11, respectively. Elongation rate differed significantly between the normal and NDR (P = 0.003) groups as well as the normal and NPDR (P = 0.001) groups. CONCLUSIONS AO-SLO can be used to detect retinal hemorheologic changes in the early stages of diabetic retinopathy.
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cone abnormalities in fundus albipunctatus associated with rdh5 mutations assessed using adaptive optics Scanning Laser Ophthalmoscopy
American Journal of Ophthalmology, 2014Co-Authors: Yukiko Makiyama, Sotaro Ooto, Masanori Hangai, Ken Ogino, Norimoto Gotoh, Akio Oishi, Nagahisa YoshimuraAbstract:Purpose To assess macular photoreceptor abnormalities in eyes with fundus albipunctatus with RDH5 mutation by using adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO). Design Prospective cross-sectional study. Methods Ten eyes with fundus albipunctatus and 11 normal eyes underwent a full ophthalmologic examination, microperimetry, spectral-domain optical coherence tomography (SD OCT), and imaging with a prototype AO-SLO system. Cone density and spatial organization of the cone mosaic were assessed using AO-SLO images. Statistical analysis was done using data from right eyes of all patients. Results Four patients had the same mutation in RDH5 (c.928delC/insGAAG), and 1 patient had a novel mutation in RDH5 (c.718delG). AO-SLO revealed the presence of small patchy dark areas representing cone loss in the macula of all eyes with fundus albipunctatus, including eyes for which fundus photographs showed no macular abnormalities and SD OCT did not reveal any visible defects in the photoreceptor layer. Compared to normal eyes, eyes with fundus albipunctatus demonstrated significantly lower cone density in areas at 0.5 mm from the center of the fovea ( P = .020). At 0.5 mm and 1.0 mm from the center of the fovea, eyes with fundus albipunctatus showed fewer cones with 6 neighbors ( P = .041 and P = .006). AO-SLO revealed hyperreflective mosaics surrounded by hyporeflective rings in areas corresponding to the retinal flecks. Conclusions Macular cone density is lower and the regularity of the macular cone mosaic spatial arrangement is disrupted in eyes with fundus albipunctatus. AO-SLO imaging is a sensitive quantitative tool for detecting photoreceptor abnormalities in eyes with fundus albipunctatus.
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macular cone abnormalities in retinitis pigmentosa with preserved central vision using adaptive optics Scanning Laser Ophthalmoscopy
PLOS ONE, 2013Co-Authors: Yukiko Makiyama, Sotaro Ooto, Akihito Uji, Masanori Hangai, Kohei Takayama, Ken Ogino, Akio Oishi, Satoko Nakagawa, Nagahisa YoshimuraAbstract:Purpose To assess macular photoreceptor abnormalities in eyes with retinitis pigmentosa (RP) with preserved central vision using adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO). Methods Fourteen eyes of 14 patients with RP (best-corrected visual acuity 20/20 or better) and 12 eyes of 12 volunteers underwent a full ophthalmologic examination, fundus autofluorescence, spectral-domain optical coherence tomography (SD-OCT), and imaging with a prototype AO-SLO system. Cone density and spatial organization of the cone mosaic were assessed using AO-SLO images. Results In 3 eyes with RP and preserved central vision, cones formed a mostly regular mosaic pattern with small patchy dark areas, and in 10 eyes, the cone mosaic patterns were less regular, and large dark regions with missing cones were apparent. Only one eye with RP demonstrated a normal, regular cone mosaic pattern. In eyes with RP, cone density was significantly lower at 0.5 mm and 1.0 mm from the center of the fovea compared to normal eyes (P<0.001 and 0.021, respectively). At 0.5 mm and 1.0 mm from the center of the fovea, a decreased number of cones had 6 neighbors in eyes with RP (P = 0.002 for both). Greater decrease in cone density was related to disruption of the photoreceptor inner segment (IS) ellipsoid band on SD-OCT images (P = 0.044); however, dark regions were seen on AO-SLO even in areas of continuous IS ellipsoid on SD-OCT. Decreased cone density correlated thinner outer nuclear layer (P = 0.029) and thinner inner segment and outer segment thickness (P = 0.011) on SD-OCT. Conclusions Cone density is decreased and the regularity of the cone mosaic spatial arrangement is disrupted in eyes with RP, even when visual acuity and foveal sensitivity are good. AO-SLO imaging is a sensitive quantitative tool for detecting photoreceptor abnormalities in eyes with RP.
Sotaro Ooto - One of the best experts on this subject based on the ideXlab platform.
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circinate partition like findings on cone mosaic imaged by adaptive optics Scanning Laser Ophthalmoscopy in eyes with inner nuclear layer microcystic changes
Retinal Cases & Brief Reports, 2017Co-Authors: Tomoko Hasegawa, Yukiko Makiyama, Kazuaki Miyamoto, Masayuki Hata, Sotaro Ooto, Nagahisa YoshimuraAbstract:PURPOSE To report cases that showed partition-like, dark areas in the cone mosaic on adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO) images in eyes with inner nuclear layer (INL) microcystic changes. METHODS Eyes with INL microcystic changes were imaged by prototype AO-SLO. RESULTS An eye with Leber hereditary optic neuropathy, an eye with traumatic optic neuropathy, and an eye with retinitis pigmentosa that showed microcystic lesions in the INL were imaged by AO-SLO. The images revealed characteristic, dark, partition-like lesions in the cone mosaic of all the eyes in areas where microcystic changes in the INL were shown by spectral domain optical coherence tomography. The AO-SLO findings in eyes with optic neuropathy were quite similar in shape and size to those seen in eyes with retinitis pigmentosa. CONCLUSION We report cases that manifest dark, partition-like areas in the cone mosaic on AO-SLO images. Microcystic lesions in the INL may affect the images of the cone mosaic.
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cone integrity in glaucoma an adaptive optics Scanning Laser Ophthalmoscopy study
American Journal of Ophthalmology, 2016Co-Authors: Tomoko Hasegawa, Yukiko Makiyama, Sotaro Ooto, Kohei Takayama, Tadamichi Akagi, Hanako Ohashi Ikeda, Hideo Nakanishi, Kenji Suda, Hiroshi Yamada, Akihito UjiAbstract:Purpose To investigate photoreceptor changes in eyes with glaucoma. Design Cross-sectional study. Methods The study included 35 eyes of 35 patients with primary open-angle glaucoma who had suffered parafoveal visual field loss at least 3 years previously, as well as 21 eyes of 21 normal subjects. Eyes with an axial length ≥26.0 mm were excluded. All subjects underwent a full ophthalmologic examination, including spectral-domain optical coherence tomography (SDOCT) and prototype adaptive-optics Scanning Laser Ophthalmoscopy (AO-SLO) imaging. Results As determined using AO-SLO, eyes with glaucoma did not differ significantly from normal eyes in terms of either cone density (26 468 ± 3392 cones/m 2 vs 26 147 ± 2700 cones/m 2 , respectively; P = .77; measured 0.5 mm from the foveal center) or cone spatial organization (ratio of hexagonal Voronoi domain: 43.7% ± 4.4% vs 44.3% ± 4.9%; P = .76; measured 0.5 mm from the foveal center). Furthermore, SDOCT showed that the 2 groups did not differ significantly in terms of the photoreceptor-related layer thickness, and that the photoreceptor ellipsoid zone band was continuous in all normal and glaucoma eyes. In glaucoma eyes with vertically asymmetric severity, the more affected side did not significantly differ from the less affected side in terms of cone density, cone spatial organization, or photoreceptor-related layer thickness. In 8 eyes (22.9%) with glaucoma, dark, partition-like areas surrounded the cones on the AO-SLO. Conclusions Both AO-SLO and SDOCT showed cone integrity in eyes with glaucoma, even in areas with visual field and nerve fiber loss. In AO-SLO, microcystic lesions in the inner nuclear layer may influence images of the cone mosaic.
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effects of age and blood pressure on the retinal arterial wall analyzed using adaptive optics Scanning Laser Ophthalmoscopy
Scientific Reports, 2015Co-Authors: Shigeta Arichika, Akihito Uji, Sotaro Ooto, Yuki Muraoka, Nagahisa YoshimuraAbstract:The wall-to-lumen ratio (WLR) of the vasculature is a promising early marker of retinal microvascular changes. Recently, adaptive optics Scanning Laser Ophthalmoscopy (AOSLO) enabled direct and noninvasive visualization of the arterial wall. Using AOSLO, we analyzed the correlation between age and WLR in 51 normal subjects. In addition, correlations between blood pressure and WLR were analyzed in 73 subjects (51 normal subjects and 22 hypertensive patients). WLR showed a strong correlation with age (r = 0.68, P < 0.0001), while outer diameter and inner diameter did not show significant correlation with age in the normal group (r = 0.13, P = 0.36 and r = −0.12, P = 0.41, respectively). In the normal and hypertensive groups, WLR showed a strong correlation with systolic and diastolic blood pressure (r = 0.60, P < 0.0001 and r = 0.65, P < 0.0001, respectively). In conclusion, AOSLO provided noninvasive and reproducible arterial measurements. WLR is an early marker of morphological changes in the retinal arteries due to age and blood pressure.
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retinal hemorheologic characterization of early stage diabetic retinopathy using adaptive optics Scanning Laser Ophthalmoscopy
Investigative Ophthalmology & Visual Science, 2014Co-Authors: Shigeta Arichika, Kazuaki Miyamoto, Sotaro Ooto, Akihito Uji, Tomoaki Murakami, Noriyuki Unoki, Shin Yoshitake, Yoko Dodo, Nagahisa YoshimuraAbstract:PURPOSE Adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO) is a noninvasive technique that allows for the direct monitoring of erythrocyte aggregates in retinal capillaries. We analyzed the retinal hemorheologic characteristics in normal subjects, diabetic patients without diabetic retinopathy (NDR), and diabetic patients with nonproliferative diabetic retinopathy (NPDR), using spatiotemporal (ST) blood flow images to visualize blood corpuscle trajectory. METHODS AO-SLO images of the parafoveal capillary network were acquired for three groups: 20 healthy volunteers, 17 diabetic patients with NDR (8 type 1 and 9 type 2 patients), and 10 diabetic patients with NPDR (4 type 1 and 6 type 2). The erythrocyte aggregate velocity assigned to a relative cardiac cycle and the elongation rate of the erythrocyte aggregate were calculated. RESULTS Careful observation revealed that flow velocity fluctuations were found with higher frequency in diabetic patients than in normal subjects. The total average velocities were 1.26 ± 0.22 mm/s in the normal group, 1.31 ± 0.21 mm/s in the NDR group, and 1.63 ± 0.35 mm/s in the NPDR group. The average velocities of the NPDR group were higher than those in the normal (P = 0.001) and NDR (P = 0.009) groups. The average elongation rates of the 3 groups were 0.67 ± 0.20, 0.39 ± 0.19, and 0.33 ± 0.11, respectively. Elongation rate differed significantly between the normal and NDR (P = 0.003) groups as well as the normal and NPDR (P = 0.001) groups. CONCLUSIONS AO-SLO can be used to detect retinal hemorheologic changes in the early stages of diabetic retinopathy.
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retinal microstructural changes in eyes with resolved branch retinal vein occlusion an adaptive optics Scanning Laser Ophthalmoscopy study
American Journal of Ophthalmology, 2014Co-Authors: Yumiko Akagikurashige, Yukiko Makiyama, Sotaro Ooto, Akihito Uji, Shigeta Arichika, Akitaka Tsujikawa, Yuki Muraoka, Tomoaki Murakami, Kyoko Kumagai, Kazuaki MiyamotoAbstract:Purpose To assess macular photoreceptor abnormalities in eyes with resolved branch retinal vein occlusion (BRVO) using adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO). Design Prospective observational cross-sectional case series. Methods After complete resolution of macular edema and retinal hemorrhage, 21 eyes (21 patients) with BRVO underwent full ophthalmologic examination and imaging with optical coherence tomography (OCT) and a prototype AO-SLO system. Cone density and spatial mosaic organization were assessed using AO-SLO images. Results Regular parafoveal cone mosaic patterns were clearly visualized with the prototype AO-SLO imaging system in the BRVO-unaffected side. However, in the side of the retina previously affected by the BRVO, cone mosaic patterns were disorganized and dark regions missing wave-guiding cones were apparent. Additionally, retinal capillaries were dilated, no longer had a uniform caliber, and had less direct paths through the retina. In the affected side, parafoveal cone density was significantly decreased, compared with the corresponding retinal area on the unaffected side ( P P Conclusions After BRVO-associated retinal hemorrhage and macular edema resolved, affected parafoveal cone density decreases and the cone mosaic spatial arrangement is disrupted, becoming more irregular. These cone microstructural abnormalities may extend to parafovea in the BRVO-unaffected side.
Joseph A Izatt - One of the best experts on this subject based on the ideXlab platform.
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super resolution retinal imaging using optically reassigned Scanning Laser Ophthalmoscopy
Nature Photonics, 2019Co-Authors: Theodore Dubose, Francesco Larocca, Sina Farsiu, Joseph A IzattAbstract:Super-resolution optical microscopy techniques have enabled the discovery and visualization of numerous phenomena in physics, chemistry and biology1-3. However, the highest resolution super-resolution techniques depend on nonlinear fluorescence phenomena and are thus inaccessible to the myriad applications that require reflective imaging4,5. One promising super-resolution technique is optical reassignment6, which so far has only shown potential for fluorescence imaging at low speeds. Here, we present novel advances in optical reassignment to adapt it for any Scanning microscopy, including reflective imaging, and enable an order of magnitude faster image acquisition than previous optical reassignment techniques. We utilized these advances to implement optically reassigned Scanning Laser Ophthalmoscopy, an in vivo super-resolution human retinal imaging device not reliant on confocal gating. Using this instrument, we achieved high-resolution imaging of living human retinal cone photoreceptor cells (determined by minimum foveal eccentricity) without adaptive optics or chemical dilation of the eye7.
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optical photon reassignment super resolved Scanning Laser Ophthalmoscopy conference presentation
Proceedings of SPIE, 2017Co-Authors: Francesco Larocca, Sina Farsiu, Theodore B Dubose, Joseph A IzattAbstract:Conventional Scanning Laser Ophthalmoscopy (SLO) utilizes a finite collection pinhole at a retinal conjugate plane to strongly reject out-of-focus light while primarily transmitting the in-focus, retinal backscattered signal. However, to improve lateral resolution, a sub-Airy disk collection pinhole is necessary, which drastically reduces the signal-to-noise ratio (SNR) of the system and is thus not commonly employed. Recently, an all-optical, super-resolution microscopy technique known as optical photon reassignment (OPRA) microscopy (also known as re-scan confocal microscopy) has been developed to bypass this fundamental tradeoff between resolution and SNR in confocal microscopy. We present a methodology and system design for obtaining super resolution in retinal imaging by combining the concepts of SLO and OPRA microscopy. The resolution improvement of the system was quantified using a 1951 USAF target at a telecentric intermediate image plane. Retinal images from human volunteers were acquired with this system both with and without using the OPRA technique to demonstrate the resolution improvement when imaging parafoveal cone photoreceptors. Finally, we quantified the resolution improvement in the retina by analyzing the radially averaged power spectrum of the retinal images.
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true color Scanning Laser Ophthalmoscopy and optical coherence tomography handheld probe
Biomedical Optics Express, 2014Co-Authors: Francesco Larocca, Sina Farsiu, Derek Nankivil, Joseph A IzattAbstract:Scanning Laser ophthalmoscopes (SLOs) are able to achieve superior contrast and axial sectioning capability compared to fundus photography. However, SLOs typically use monochromatic illumination and are thus unable to extract color information of the retina. Previous color SLO imaging techniques utilized multiple Lasers or narrow band sources for illumination, which allowed for multiple color but not “true color” imaging as done in fundus photography. We describe the first “true color” SLO, handheld color SLO, and combined color SLO integrated with a spectral domain optical coherence tomography (OCT) system. To achieve accurate color imaging, the SLO was calibrated with a color test target and utilized an achromatizing lens when imaging the retina to correct for the eye’s longitudinal chromatic aberration. Color SLO and OCT images from volunteers were then acquired simultaneously with a combined power under the ANSI limit. Images from this system were then compared with those from commercially available SLOs featuring multiple narrow-band color imaging.
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handheld simultaneous Scanning Laser Ophthalmoscopy and optical coherence tomography system
Biomedical Optics Express, 2013Co-Authors: Francesco Larocca, Sina Farsiu, Derek Nankivil, Joseph A IzattAbstract:Scanning Laser Ophthalmoscopy (SLO) and optical coherence tomography (OCT) are widely used retinal imaging modalities that can assist in the diagnosis of retinal pathologies. The combination of SLO and OCT provides a more comprehensive imaging system and a method to register OCT images to produce motion corrected retinal volumes. While high quality, bench-top SLO-OCT systems have been discussed in the literature and are available commercially, there are currently no handheld designs. We describe the first design and fabrication of a handheld SLO/spectral domain OCT probe. SLO and OCT images were acquired simultaneously with a combined power under the ANSI limit. High signal-to-noise ratio SLO and OCT images were acquired simultaneously from a normal subject with visible motion artifacts. Fully automated motion estimation methods were performed in post-processing to correct for the inter- and intra-frame motion in SLO images and their concurrently acquired OCT volumes. The resulting set of reconstructed SLO images and the OCT volume were without visible motion artifacts. At a reduced field of view, the SLO resolved parafoveal cones without adaptive optics at a retinal eccentricity of 11° in subjects with good ocular optics. This system may be especially useful for imaging young children and subjects with less stable fixation.
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interlaced spectrally encoded confocal Scanning Laser Ophthalmoscopy and spectral domain optical coherence tomography
Biomedical Optics Express, 2010Co-Authors: Yuankai K Tao, Sina Farsiu, Joseph A IzattAbstract:Scanning Laser Ophthalmoscopy (SLO) and spectral domain optical coherence tomography (SDOCT) have become essential clinical diagnostic tools in ophthalmology by allowing for video-rate noninvasive en face and depth-resolved visualization of retinal structure. Current generation multimodal imaging systems that combine both SLO and OCT as a means of image tracking remain complex in their hardware implementations. Here, we combine a spectrally encoded confocal Scanning Laser ophthalmoscope (SECSLO) with an ophthalmic SDOCT system. This novel implementation of an interlaced SECSLO-SDOCT system allows for video-rate SLO fundus images to be acquired alternately with high-resolution SDOCT B-scans as a means of image aiming, guidance, and registration as well as motion tracking. The system shares the illumination source, detection system, and Scanning optics between both SLO and OCT as a method of providing a simple multimodal ophthalmic imaging system that can readily be implemented as a table-top or hand-held device.
Austin Roorda - One of the best experts on this subject based on the ideXlab platform.
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high resolution eye tracking using Scanning Laser Ophthalmoscopy
Proceedings of the 11th ACM Symposium on Eye Tracking Research & Applications, 2019Co-Authors: Norick R Bowers, Agostino Gibaldi, Emma Alexander, Martin S Banks, Austin RoordaAbstract:Current eye-tracking techniques rely primarily on video-based tracking of components of the anterior surfaces of the eye. However, these trackers have several limitations. Their limited resolution precludes study of small fixational eye motion. Furthermore, many of these trackers rely on calibration procedures that do not offer a way to validate their eye motion traces. By comparison, retinal-image-based trackers can track the motion of the retinal image directly, at frequencies greater than 1kHz and with subarcminute accuracy. The retinal image provides a way to validate the eye position at any point in time, offering an unambiguous record of eye motion as a reference for the eye trace. The benefits of using Scanning retinal imaging systems as eye trackers, however, comes at the price of different problems that are not present in video-based systems, and need to be solved to obtain robust eye traces. The current abstract provides an overview of retinal-image-based eye tracking methods, provides preliminary eye-tracking results from a tracking Scanning-Laser ophthalmoscope (TSLO), and proposes a new binocular line-Scanning eye-tracking system.
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versatile multi detector scheme for adaptive optics Scanning Laser Ophthalmoscopy
Biomedical Optics Express, 2018Co-Authors: Sanam Mozaffari, Pavan Tiruveedhula, Volker Jaedicke, Francesco Larocca, Austin RoordaAbstract:Adaptive optics Scanning Laser Ophthalmoscopy (AOSLO) is a powerful tool for imaging the retina at high spatial and temporal resolution. In this paper, we present a multi-detector scheme for AOSLO which has two main configurations: pixel reassignment and offset aperture imaging. In this detection scheme, the single element detector of the standard AOSLO is replaced by a fiber bundle which couples the detected light into multiple detectors. The pixel reassignment configuration enables high resolution imaging with an increased light collection. The increase in signal-to-noise ratio (SNR) from this configuration can improve the accuracy of motion registration techniques. The offset aperture imaging configuration enhances the detection of multiply scattered light, which improves the contrast of retinal vasculature and inner retinal layers similar to methods such as nonconfocal split-detector imaging and multi-offset aperture imaging.
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versatile multi detector scheme for adaptive optics Scanning Laser Ophthalmoscopy
bioRxiv, 2018Co-Authors: Sanam Mozaffari, Pavan Tiruveedhula, Volker Jaedicke, Francesco Larocca, Austin RoordaAbstract:Adaptive Optics Scanning Laser Ophthalmoscopy (AOSLO) is a powerful tool for imaging the retina at high spatial and temporal resolution. In this paper, we present a multi-detector scheme for AOSLO which has two main configurations: pixel reassignment and offset aperture imaging. In this detection scheme, the single element detector of the standard AOSLO is replaced by a fiber bundle which couples the detected light into multiple detectors. The pixel reassignment configuration allows for more light throughput while maintaining optimal confocal resolution. The increase in signal-to-noise ratio (SNR) from this configuration can improve the accuracy of motion registration techniques. The offset aperture imaging configuration enhances the detection of multiply scattered light, which improves the contrast of retinal vasculature and inner retinal layers similar to methods such as nonconfocal split-detector imaging and multi-offset aperture imaging.
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relationship between foveal cone structure and visual acuity measured with adaptive optics Scanning Laser Ophthalmoscopy in retinal degeneration
Investigative Ophthalmology & Visual Science, 2018Co-Authors: Katharina G Foote, Shane Griffin, Panagiota Loumou, Kavitha Ratnam, Austin Roorda, Travis C Porco, Jacque L. DuncanAbstract:Purpose:To evaluate foveal function in patients with inherited retinal degenerations (IRD) by measuring visual acuity (VA) after correction of higher-order aberrations. Methods:Adaptive optics Scanning Laser Ophthalmoscopy (AOSLO) was used to image cones in 4 healthy subjects and 15 patients with IRD. The 840-nm Scanning Laser delivered an "E" optotype to measure AOSLO-mediated VA (AOSLO-VA). Cone spacing was measured at the preferred retinal locus by two independent graders and the percentage of cones below the average density of 47 age-similar healthy subjects was computed. Cone spacing was correlated with best-corrected VA measured with the Early Treatment of Diabetic Retinopathy Study protocol (ETDRS-VA), AOSLO-VA, and foveal sensitivity. Results:ETDRS-VA significantly correlated with AOSLO-VA (ρ = 0.79, 95% confidence interval [CI] 0.5-0.9). Cone spacing correlated with AOSLO-VA (ρ = 0.54, 95% CI 0.02-0.7), and negatively correlated with ETDRS letters read (ρ = -0.64, 95% CI -0.8 to -0.2). AOSLO-VA remained ≥20/20 until cones decreased to 40.2% (CI 31.1-45.5) below normal. Similarly, ETDRS-VA remained ≥20/20 until cones were 42.0% (95% CI 36.5-46.1) below normal. Cone spacing z scores negatively correlated with foveal sensitivity (ρ = -0.79, 95% CI -0.9 to -0.4) and foveal sensitivity was ≥35 dB until cones were 43.1% (95% CI 39.3-46.6) below average. Conclusions:VA and foveal cone spacing were weakly correlated until cones were reduced by 40% to 43% below normal. The relationship suggests that VA is an insensitive measure of foveal cone survival; cone spacing may be a more sensitive measure of cone loss.
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relationship between foveal cone structure and visual acuity measured with adaptive optics Scanning Laser Ophthalmoscopy in retinal degeneration
Investigative Ophthalmology & Visual Science, 2018Co-Authors: Katharina G Foote, Shane Griffin, Panagiota Loumou, Kavitha Ratnam, Austin Roorda, Travis C Porco, Jia Qin, Jacque L. DuncanAbstract:Author(s): Foote, Katharina G; Loumou, Panagiota; Griffin, Shane; Qin, Jia; Ratnam, Kavitha; Porco, Travis C; Roorda, Austin; Duncan, Jacque L | Abstract: PurposeTo evaluate foveal function in patients with inherited retinal degenerations (IRD) by measuring visual acuity (VA) after correction of higher-order aberrations.MethodsAdaptive optics Scanning Laser Ophthalmoscopy (AOSLO) was used to image cones in 4 healthy subjects and 15 patients with IRD. The 840-nm Scanning Laser delivered an "E" optotype to measure AOSLO-mediated VA (AOSLO-VA). Cone spacing was measured at the preferred retinal locus by two independent graders and the percentage of cones below the average density of 47 age-similar healthy subjects was computed. Cone spacing was correlated with best-corrected VA measured with the Early Treatment of Diabetic Retinopathy Study protocol (ETDRS-VA), AOSLO-VA, and foveal sensitivity.ResultsETDRS-VA significantly correlated with AOSLO-VA (ρ = 0.79, 95% confidence interval [CI] 0.5-0.9). Cone spacing correlated with AOSLO-VA (ρ = 0.54, 95% CI 0.02-0.7), and negatively correlated with ETDRS letters read (ρ = -0.64, 95% CI -0.8 to -0.2). AOSLO-VA remained ≥20/20 until cones decreased to 40.2% (CI 31.1-45.5) below normal. Similarly, ETDRS-VA remained ≥20/20 until cones were 42.0% (95% CI 36.5-46.1) below normal. Cone spacing z scores negatively correlated with foveal sensitivity (ρ = -0.79, 95% CI -0.9 to -0.4) and foveal sensitivity was ≥35 dB until cones were 43.1% (95% CI 39.3-46.6) below average.ConclusionsVA and foveal cone spacing were weakly correlated until cones were reduced by 40% to 43% below normal. The relationship suggests that VA is an insensitive measure of foveal cone survival; cone spacing may be a more sensitive measure of cone loss.
Masanori Hangai - One of the best experts on this subject based on the ideXlab platform.
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cone abnormalities in fundus albipunctatus associated with rdh5 mutations assessed using adaptive optics Scanning Laser Ophthalmoscopy
American Journal of Ophthalmology, 2014Co-Authors: Yukiko Makiyama, Sotaro Ooto, Masanori Hangai, Ken Ogino, Norimoto Gotoh, Akio Oishi, Nagahisa YoshimuraAbstract:Purpose To assess macular photoreceptor abnormalities in eyes with fundus albipunctatus with RDH5 mutation by using adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO). Design Prospective cross-sectional study. Methods Ten eyes with fundus albipunctatus and 11 normal eyes underwent a full ophthalmologic examination, microperimetry, spectral-domain optical coherence tomography (SD OCT), and imaging with a prototype AO-SLO system. Cone density and spatial organization of the cone mosaic were assessed using AO-SLO images. Statistical analysis was done using data from right eyes of all patients. Results Four patients had the same mutation in RDH5 (c.928delC/insGAAG), and 1 patient had a novel mutation in RDH5 (c.718delG). AO-SLO revealed the presence of small patchy dark areas representing cone loss in the macula of all eyes with fundus albipunctatus, including eyes for which fundus photographs showed no macular abnormalities and SD OCT did not reveal any visible defects in the photoreceptor layer. Compared to normal eyes, eyes with fundus albipunctatus demonstrated significantly lower cone density in areas at 0.5 mm from the center of the fovea ( P = .020). At 0.5 mm and 1.0 mm from the center of the fovea, eyes with fundus albipunctatus showed fewer cones with 6 neighbors ( P = .041 and P = .006). AO-SLO revealed hyperreflective mosaics surrounded by hyporeflective rings in areas corresponding to the retinal flecks. Conclusions Macular cone density is lower and the regularity of the macular cone mosaic spatial arrangement is disrupted in eyes with fundus albipunctatus. AO-SLO imaging is a sensitive quantitative tool for detecting photoreceptor abnormalities in eyes with fundus albipunctatus.
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macular cone abnormalities in retinitis pigmentosa with preserved central vision using adaptive optics Scanning Laser Ophthalmoscopy
PLOS ONE, 2013Co-Authors: Yukiko Makiyama, Sotaro Ooto, Akihito Uji, Masanori Hangai, Kohei Takayama, Ken Ogino, Akio Oishi, Satoko Nakagawa, Nagahisa YoshimuraAbstract:Purpose To assess macular photoreceptor abnormalities in eyes with retinitis pigmentosa (RP) with preserved central vision using adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO). Methods Fourteen eyes of 14 patients with RP (best-corrected visual acuity 20/20 or better) and 12 eyes of 12 volunteers underwent a full ophthalmologic examination, fundus autofluorescence, spectral-domain optical coherence tomography (SD-OCT), and imaging with a prototype AO-SLO system. Cone density and spatial organization of the cone mosaic were assessed using AO-SLO images. Results In 3 eyes with RP and preserved central vision, cones formed a mostly regular mosaic pattern with small patchy dark areas, and in 10 eyes, the cone mosaic patterns were less regular, and large dark regions with missing cones were apparent. Only one eye with RP demonstrated a normal, regular cone mosaic pattern. In eyes with RP, cone density was significantly lower at 0.5 mm and 1.0 mm from the center of the fovea compared to normal eyes (P<0.001 and 0.021, respectively). At 0.5 mm and 1.0 mm from the center of the fovea, a decreased number of cones had 6 neighbors in eyes with RP (P = 0.002 for both). Greater decrease in cone density was related to disruption of the photoreceptor inner segment (IS) ellipsoid band on SD-OCT images (P = 0.044); however, dark regions were seen on AO-SLO even in areas of continuous IS ellipsoid on SD-OCT. Decreased cone density correlated thinner outer nuclear layer (P = 0.029) and thinner inner segment and outer segment thickness (P = 0.011) on SD-OCT. Conclusions Cone density is decreased and the regularity of the cone mosaic spatial arrangement is disrupted in eyes with RP, even when visual acuity and foveal sensitivity are good. AO-SLO imaging is a sensitive quantitative tool for detecting photoreceptor abnormalities in eyes with RP.
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image quality improvement in adaptive optics Scanning Laser Ophthalmoscopy assisted capillary visualization using b spline based elastic image registration
PLOS ONE, 2013Co-Authors: Akihito Uji, Sotaro Ooto, Masanori Hangai, Shigeta Arichika, Nagahisa YoshimuraAbstract:Purpose To investigate the effect of B-spline-based elastic image registration on adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO)-assisted capillary visualization. Methods AO-SLO videos were acquired from parafoveal areas in the eyes of healthy subjects and patients with various diseases. After nonlinear image registration, the image quality of capillary images constructed from AO-SLO videos using motion contrast enhancement was compared before and after B-spline-based elastic (nonlinear) image registration performed using ImageJ. For objective comparison of image quality, contrast-to-noise ratios (CNRS) for vessel images were calculated. For subjective comparison, experienced ophthalmologists ranked images on a 5-point scale. Results All AO-SLO videos were successfully stabilized by elastic image registration. CNR was significantly higher in capillary images stabilized by elastic image registration than in those stabilized without registration. The average ratio of CNR in images with elastic image registration to CNR in images without elastic image registration was 2.10 ± 1.73, with no significant difference in the ratio between patients and healthy subjects. Improvement of image quality was also supported by expert comparison. Conclusions Use of B-spline-based elastic image registration in AO-SLO-assisted capillary visualization was effective for enhancing image quality both objectively and subjectively.
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comparison of cone pathologic changes in idiopathic macular telangiectasia types 1 and 2 using adaptive optics Scanning Laser Ophthalmoscopy
American Journal of Ophthalmology, 2013Co-Authors: Sotaro Ooto, Masanori Hangai, Akitaka Tsujikawa, Kohei Takayama, Masaaki Hanebuchi, Naoko Uedaarakawa, Kenji Yamashiro, Akio Oishi, Nagahisa YoshimuraAbstract:Purpose To compare pathologic changes in the photoreceptors of eyes with idiopathic macular telangiectasia types 1 and 2 using adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO). Design Prospective cross-sectional study. Methods Eleven eyes with idiopathic macular telangiectasia type 1, 14 eyes with type 2, and 10 normal eyes underwent a full ophthalmologic examination, spectral-domain optical coherence tomography (SD-OCT), and imaging with an original prototype AO-SLO system. All eyes with idiopathic macular telangiectasia were examined with fluorescein angiography (FA), confocal blue reflectance, and microperimetry. Results Compared with normal eyes (29 017 ± 5507 cones/mm 2 ), those with idiopathic macular telangiectasia type 1 had significantly lower cone density on the temporal side (18 427 ± 4908 cones/mm 2 , P = .010). The FA leakage area (5.90 ± 3.23 mm 2 ) was larger than the dark regions (2.45 ± 2.40 mm 2 ) on AO-SLO ( P = .003)—which were observed only in the FA leakage area. Compared with normal eyes, those with idiopathic macular telangiectasia type 2 had significantly lower cone density in all areas ( P P = .010; type 2: P Conclusions Idiopathic macular telangiectasia type-specific differences in the distribution of photoreceptor abnormalities were shown in the AO-SLO images. For both idiopathic macular telangiectasia types 1 and 2, visual impairment was associated with cone damage.
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objective assessment of foveal cone loss ratio in surgically closed macular holes using adaptive optics Scanning Laser Ophthalmoscopy
PLOS ONE, 2013Co-Authors: Satoshi Yokota, Sotaro Ooto, Masanori Hangai, Kohei Takayama, Masaaki Hanebuchi, Naoko Uedaarakawa, Yuki Yoshihara, Nagahisa YoshimuraAbstract:Purpose To use adaptive optics Scanning Laser Ophthalmoscopy (AO-SLO) to quantify cone loss ratio in the foveola in order to assess foveal cone status and to investigate relationships between foveal structural abnormalities and visual function in patients with macular hole (MH) after surgery. Methods We evaluated 10 normal eyes of 10 healthy volunteers and 19 eyes of 18 patients in whom anatomically successful MH closure had been performed. All subjects underwent a comprehensive ophthalmologic examination that included measurements of spectral-domain optical coherence tomography and AO-SLO. Results On AO-SLO regular cone mosaic was seen in all normal eyes whereas dark regions suggesting cone loss were seen in all eyes after MH repair. Visual acuity was better in eyes without dark regions at the center of the fovea than in eyes with them (P = 0.001). Cone loss ratio in the foveola correlated with postoperative visual acuity (P<0.001), mean foveal sensitivity (P = 0.029), thinner inner and outer segments at the center of the fovea (P = 0.002), larger size of the disrupted inner and outer segment junction line (P = 0.018), and cone outer segment tip line (P<0.001). Cone loss ratio in the foveola was significantly greater in eyes that had moderately reflective foveal lesions after surgery (P = 0.006). Conclusions AO-SLO is a useful means of assessing foveal cone damage objectively and quantitatively. The location and extent of cone damage, especially if it involves the foveola, is an important factor determining visual function after MH surgery.
