scholarly journals Exploring Multimodal Ocular Imaging for Retinal Biomarkers of Alzheimer’s Disease, Frontotemporal Dementia, and Cognitively Normal Subjects

2021 ◽  
Author(s):  
Kelly Z. Young ◽  
Nikhila S. Khandwala ◽  
Omar Moinuddin ◽  
Benjamin K. Young ◽  
Warren Pan ◽  
...  
Keyword(s):  
Frontotemporal Dementia ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Fundus Autofluorescence ◽  
Fundus Photography ◽  
Retinal Layer ◽  
Wide Field ◽  
Amyloid Burden ◽  
Fiber Layer ◽  
Ocular Imaging

Abstract Background and ObjectivesAlzheimer’s disease (AD) and frontotemporal dementia (FTD) are difficult to reliably differentiate clinically. While their distinct pathologies may be captured by existing diagnostic modalities, these are expensive, time-consuming, and often inaccessible. Dementias are associated with visual dysfunctions, perhaps due to changes in the retina, a developmental outgrowth of the central nervous system. We explore the role of multimodal ocular imaging in the diagnosis of two dementias, AD and FTD.MethodsWe recruited 5 AD participants, 2 FTD participants, and 9 age-matched controls. Each participant underwent comprehensive ophthalmologic examination and imaging (optical coherence tomography (OCT), OCT-angiography (OCTA), wide-field fundus photography, near-infrared imaging, and fundus autofluorescence). Ocular findings were correlated with cerebral amyloid burden, as measured by [11C]PiB PET.ResultsOCT analysis identified a trend toward differences in retinal nerve fiber layer (RNFL) thicknesses among dementia subtypes (p = 0.064). AD eyes had increased RNFL thicknesses compared to FTD (p = 0.046) and control eyes (p = 0.046), and AD RNFL thickness was positively associated with amyloid burden (p = 0.037). OCTA fractal analysis revealed decreased vascular complexity within the retinal superficial vascular complex in AD compared to FTD eyes (p = 0.035). Lastly, fundus autofluorescence demonstrated increased signal intensity in AD eyes compared to control eyes (p = 0.046). However, these findings were not statistically significant following correction for multiple comparisons.DiscussionDespite identifying trends toward differences in retinal layer thicknesses unique to individuals with AD and FTD, our study suggests that changes in retinal thicknesses alone may not serve as reliable biomarkers for distinguishing between dementia subtypes. However, multiple ocular imaging modalities may be considered in conjunction with clinical presentation to aid in diagnosing and monitoring AD and FTD.Trial registrationThe study was prospectively registered on clinicaltrials.gov (NCT03699644) on October 9, 2018.

scholarly journals Substellar and low-mass dwarf identification with near-infrared imaging space observatories

2018 ◽  
Vol 620 ◽  
pp. A132 ◽  
Author(s):  
B. W. Holwerda ◽  
J. S. Bridge ◽  
R. Ryan ◽  
M. A. Kenworthy ◽  
N. Pirzkal ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
High Redshift ◽  
Brown Dwarfs ◽  
Wide Field ◽  
Space Telescope ◽  
Low Mass ◽  
Space Observatories ◽  
Broad Type ◽  
Selection Of

Aims. We aim to evaluate the near-infrared colors of brown dwarfs as observed with four major infrared imaging space observatories: the Hubble Space Telescope (HST), the James Webb Space Telescope (JWST), the Euclid mission, and the WFIRST telescope. Methods. We used the SPLAT SPEX/ISPEX spectroscopic library to map out the colors of the M-, L-, and T-type dwarfs. We have identified which color–color combination is optimal for identifying broad type and which single color is optimal to then identify the subtype (e.g., T0-9). We evaluated each observatory separately as well as the narrow-field (HST and JWST) and wide-field (Euclid and WFIRST) combinations. Results. The Euclid filters perform equally well as HST wide filters in discriminating between broad types of brown dwarfs. WFIRST performs similarly well, despite a wider selection of filters. However, subtyping with any combination of Euclid and WFIRST observations remains uncertain due to the lack of medium, or narrow-band filters. We argue that a medium band added to the WFIRST filter selection would greatly improve its ability to preselect brown dwarfs its imaging surveys. Conclusions. The HST filters used in high-redshift searches are close to optimal to identify broad stellar type. However, the addition of F127M to the commonly used broad filter sets would allow for unambiguous subtyping. An improvement over HST is one of two broad and medium filter combinations on JWST: pairing F140M with either F150W or F162M discriminates very well between subtypes.

scholarly journals Optical Coherence Tomography Angiography (OCT-A) in a Patient with Occult Retinal Dysfunction

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Juliana Wons ◽  
Jana Dinges ◽  
Matthias D. Becker ◽  
Stephan Michels
Keyword(s):  
Optical Coherence Tomography ◽  
Visual Field ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Imaging Techniques ◽  
Visual Field Defects ◽  
Retinal Layer ◽  
Optical Coherence ◽  
Large Area ◽  
Sd Oct

Multimodal imaging techniques were performed in a patient with a newly emerged visual field defect; a missing retinal lesion on fundus examination made the diagnosis challenging but infrared imaging showed a larger area of retinal abnormality temporal to the fovea. Indocyanine green angiography (IA) showed late hypofluorescence and there was mild hyperautofluorescence which is known from acute zonal occult outer retinopathy (AZOOR). Despite normal fluorescein angiography (FA) results, a perfusion loss in the outer retinal layer was detected by OCT-A. Similar OCT-A findings were recently described in patients with acute macular neuroretinopathy (AMN). Methods. The methods included FA and IA, spectral domain optical coherence tomography (SD-OCT), near infrared imaging, and autofluorescence imaging (AF), as well as OCT-A. Patient. A 36-year-old patient who suffered from acute symptoms of photopsia and scotoma on her left eye. She had an influenza-like illness two weeks earlier. The scotoma could be verified by visual field testing. Results. The affected retinal zone showed mild fading of external limiting membrane (ELM) and a disorganisation of the ellipsoid zone (EZ) on SD-OCT. OCT-A revealed a large area of reduced perfusion in the outer retinal vascular layer. Conclusion. OCT-A can help to detect reduced capillary network in patients with visual field defects and no visible fundus changes. This case seems to have features of different occult retinal disorders such as AZOOR and AMN.

Clinical Signs, Imaging, Diagnosis and Differential Diagnosis of Rhegmatogenous Retinal Detachment

2019 ◽  
pp. 154-162
Keyword(s):  
Differential Diagnosis ◽  
Retinal Detachment ◽  
Ultrasound Imaging ◽  
Rhegmatogenous Retinal Detachment ◽  
Fundus Autofluorescence ◽  
Clinical Signs ◽  
Vitreous Hemorrhage ◽  
Fundus Photography ◽  
Visual Field Defects ◽  
Wide Field

Photopsia, floaters, visual field defects, loss in visual acuity, periocular pain, and dyschromatopsia are symptoms of rhegmatogenous retinal detachment in which early signs are Weiss ring, pigmented cells in anterior vitreous (tobacco dust sign), a general decrease in intraocular pressure and retinal detachment in a convex configuration. On the other hand, the demarcation line, secondary retinal cysts, and proliferative vitreoretinopathy are some of the late findings of detachment. Imaging of the retina is crucial in rhegmatogenous retinal detachment. Fundus photography, wide-field imaging systems, optical coherence tomography, and fundus autofluorescence tomography are beneficial for documentation and monitoring progression. Ultrasound imaging, computerized tomography, and magnetic resonance imaging may be helpful when the retina cannot be visualized in cases like vitreous hemorrhage and dense cataract. Diagnosis can be made with indirect ophthalmoscopy with indentation, and ultrasound imaging in an opaque medium. Differential diagnosis of rhegmatogenous retinal detachment is exudative and tractional detachment, as well as lesions that can mimic retinal detachment such as retinoschisis, intraretinal macrocysts, choroidal detachment, vitreous opacities and white with or without pressure lesions.

WIDE-FIELD NEAR-INFRARED IMAGING OF THE L1551 DARK CLOUD

2009 ◽  
Vol 694 (1) ◽  
pp. 582-592 ◽  
Author(s):  
Masahiko Hayashi ◽  
Tae-Soo Pyo
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Wide Field ◽  
Near Infrared Imaging ◽  
Dark Cloud

scholarly journals Application of wide-field infrared reflectance imaging in retinoschisis, retinal detachments, and schisis detachments

2019 ◽  
Vol 5 (S1) ◽  
Author(s):  
Himanshu K. Banda ◽  
Anjali Shah ◽  
Gaurav K. Shah
Keyword(s):  
Retinal Detachment ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Anterior Segment ◽  
Infrared Light ◽  
Main Body ◽  
Wide Field ◽  
Wide Angle ◽  
Infrared Reflectance ◽  
Non Invasive

Abstract Background Retinoschisis and retinal detachment are distinguished based on features in clinical examination. Even to skilled examiners, some cases may be diagnostic challenges. Infrared and wide-angle infrared reflectance imaging are relatively new modalities that can provide additional diagnostic information. Non-contact infrared reflectance imaging (also described as near-infrared imaging) highlights sub-retinal features which may otherwise be obscured by standard retinal photography. It is non-invasive and uses the retina’s ability to absorb, reflect or scatter infrared light to produce high quality images. Main body The aim of this review is to describe the role of wide-field infrared imaging in screening, diagnosing, and monitoring structural peripheral retinal disorders including retinoschisis, retinal detachment or combined retinoschisis rhegmatogenous detachments. Infrared imaging can also be used to monitor anterior segment inflammation. Heidelberg Wide-Field Module lens and Heidelberg Spectralis® HRA + OCT machine (Heidelberg Engineering, Heidelberg, Germany) were used to obtain noncontact, wide-field infrared images on each study eye. Pseudocolor photos were captured by Optos Optomap® (Optos, Inc, Massachusetts, USA). Conclusion Wide angle infrared imaging offers a quick, noncontact, and noninvasive way to help specialists accurately diagnose, monitor for progression, and educate patients about retinal detachment, retinoschisis and even anterior segment inflammation.

scholarly journals Reddening-independent quasar selection from a wide-field optical and near-infrared imaging survey

2002 ◽  
Vol 337 (3) ◽  
pp. 1153-1162 ◽  
Author(s):  
R. G. Sharp ◽  
C. N. Sabbey ◽  
A. K. Vivas ◽  
A. Oemler ◽  
R. G. McMahon ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Wide Field ◽  
Near Infrared Imaging

scholarly journals Multi-Color Surface Photometry of Nearby Galaxies

1998 ◽  
Vol 179 ◽  
pp. 285-286
Author(s):  
T. Ichikawa ◽  
N. Itoh ◽  
K. Yanagisawa
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Spiral Galaxies ◽  
Stellar Structure ◽  
Star Formation History ◽  
Optical Observations ◽  
Wide Field ◽  
Formation History

Near-infrared (NIR) emission in galaxies is mainly radiated by old population low temperature stars, which construct the basic stellar structure and keep the trails of past galaxy evolution. On the other hand, optical observations show recent star formation activity, especially in spiral galaxies. Therefore multi-color observations from optical to near-infrared wavelengths are very important to understand the past and recent star-formation history. Nearby large galaxies are well studied not only in optical but also in mid- and far-infrared by IRAS, CO and HI radio observations. However, the study in the near-infrared is still limited because large format arrays are not common. Here we show a wide-field, near-infrared imaging of nearby elliptical and spiral galaxies and discuss their star-formation history.

scholarly journals Ocular biomarkers for cognitive impairment in nonagenarians; a prospective cross-sectional study

2019 ◽  
Author(s):  
Jacoba Alida van de Kreeke ◽  
Nienke Legdeur ◽  
Maryam Badissi ◽  
H. Ton Nguyen ◽  
Elles Konijnenberg ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Layer Thickness ◽  
Cross Sectional Study ◽  
Fundus Photography ◽  
Cognitively Impaired ◽  
Retinal Layer ◽  
Sectional Study ◽  
Fiber Layer ◽  
Cross Sectional ◽  
Nerve Fiber Layer Thickness

Abstract Background: Ocular imaging receives much attention as a source of potential biomarkers for dementia. In the present study, we analyze these ocular biomarkers in cognitively impaired and healthy participants in a population aged over 90 years (= nonagenarian), and elucidate the effects of age on these biomarkers. Methods: For this prospective cross-sectional study, we included individuals from the EMIF-AD 90+ study, consisting of a cognitively healthy (N=67) and cognitively impaired group (N=33), and the EMIF-AD PreclinAD study, consisting of cognitively healthy controls aged ≥60 (N=198). Participants underwent Optical Coherence Tomography (OCT) and fundus photography of both eyes. OCT was used to asses total and individual inner retinal layer thickness in the macular region (Early Treatment Diabetic Retinopathy Study circles) as well as peripapillary retinal nerve fiber layer thickness, fundus images were analyzed with Singapore I Vessel Assessment to obtain 7 retinal vascular parameters. Values for both eyes were averaged. Differences in ocular biomarkers between the 2 nonagenarian groups were analyzed using linear regression, differences between the individual nonagenarian groups and controls were analyzed using generalized estimating equations. Results: Ocular biomarkers did not differ between the healthy and cognitively impaired nonagenarian groups. Both nonagenarian groups differed in most ocular biomarkers from the younger controls. Conclusion: Ocular biomarkers were not associated with cognitive impairment in nonagenarians, making their use as a screening tool for dementing disorders in this group limited. However, ocular biomarkers were significantly associated with chronological age, which were very similar to those ascribed to occur in Alzheimer’s Disease.

scholarly journals Fundus Autofluorescence and Spectral Domain OCT in Central Serous Chorioretinopathy

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Luiz Roisman ◽  
Daniel Lavinsky ◽  
Fernanda Magalhaes ◽  
Fabio Bom Aggio ◽  
Nilva Moraes ◽  
...  
Keyword(s):  
Fluorescein Angiography ◽  
Central Serous Chorioretinopathy ◽  
Near Infrared ◽  
Pigment Epithelium ◽  
Fundus Autofluorescence ◽  
Subretinal Fluid ◽  
Spectral Domain ◽  
Fundus Photography ◽  
Cross Sectional ◽  
Spectral Domain Oct

Background. To describe the standard autofluorescence (FAF), the near infrared autofluorescence (NIA) and optical coherence tomography (OCT) patterns in central serous chorioretinopathy, correlating them with fluorescein angiography.Methods. Cross-sectional observational study, in which patients with at least seven months of CSC underwent ophthalmologic examination, fundus photography, FAF, NIA, fluorescein angiography (FA), and spectral-domain OCT.Results. Seventeen eyes of thirteen patients were included. The presentation features were a mottled hyperFAF in the detached area and areas with pigment mottling. NIA images showed areas of hyperNIA similar to FAF and localized areas of hypoNIA, which correlated with the points of leakage in the FA. OCT showed pigment epithelium detachment at the location of these hypoNIA spots.Discussion. FAF showed increased presence of fluorophores in the area of retinal detachment, which is believed to appear secondary to lipofuscin accumulation in the RPE or the presence of debris in the subretinal fluid. NIA has been related to the choroidal melanin content and there were areas of both increased and decreased NIA, which could be explained by damage ahead the retina, basically RPE and choroid. These findings, along with the PEDs found in the areas of hypoNIA, support the notion of a primary choroidal disease in CSC.

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