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  1. Article: Combining fluorescence lifetime with spectral information in fluorescence lifetime imaging ophthalmoscopy (FLIO).

    Hammer, Martin / Simon, Rowena / Meller, Daniel / Klemm, Matthias

    Biomedical optics express

    2022  Volume 13, Issue 10, Page(s) 5483–5494

    Abstract: Fluorescence lifetime imaging ophthalmoscopy (FLIO) provides information on fluorescence lifetimes in two spectral channels as well as the peak emission wavelength (PEW) of the fluorescence. Here, we combine these measures in an integral three- ... ...

    Abstract Fluorescence lifetime imaging ophthalmoscopy (FLIO) provides information on fluorescence lifetimes in two spectral channels as well as the peak emission wavelength (PEW) of the fluorescence. Here, we combine these measures in an integral three-dimensional lifetime-PEW metric vector and determine a normal range for this vector from measurements in young healthy subjects. While for these control subjects 97 (±8) % (median (interquartile range)) of all para-macular pixels were covered by this normal vector range, it was 67 (±55) % for the elderly healthy, 38 (±43) % for age-related macular degeneration (AMD)-suspect subjects, and only 6 (±4) % for AMD patients. The vectors were significantly different for retinal pigment epithelium (RPE) lesions in AMD patients from that of non-affected tissue (p < 0.001). Lifetime- PEW plots allowed to identify possibly pathologic fundus areas by fluorescence parameters outside a 95% quantile per subject. In a patient follow-up, changes in fluorescence parameters could be traced in the lifetime-PEW metric, showing their change over disease progression.
    Language English
    Publishing date 2022-09-26
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2572216-5
    ISSN 2156-7085
    ISSN 2156-7085
    DOI 10.1364/BOE.457946
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Impact of cataract on the spectral measurement of fundus autofluorescence.

    Simon, Rowena / Brauer, Jakob Lauritz / Meller, Daniel / Hammer, Martin

    Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie

    2022  Volume 260, Issue 6, Page(s) 2057–2059

    MeSH term(s) Cataract/diagnosis ; Fluorescein Angiography ; Fundus Oculi ; Humans ; Tomography, Optical Coherence
    Language English
    Publishing date 2022-01-12
    Publishing country Germany
    Document type Letter
    ZDB-ID 8435-9
    ISSN 1435-702X ; 0721-832X
    ISSN (online) 1435-702X
    ISSN 0721-832X
    DOI 10.1007/s00417-022-05554-4
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Fluorescence lifetime and peak emission wavelength differ between AMD patients with soft drusen and sub-retinal drusenoid deposits.

    Simon, Rowena / Curcio, Christine A / Weber, Sebastian / Meller, Daniel / Hammer, Martin

    Acta ophthalmologica

    2022  Volume 100, Issue 6, Page(s) e1354–e1355

    MeSH term(s) Fluorescence ; Geographic Atrophy ; Humans ; Retinal Drusen/diagnosis ; Retinal Pigment Epithelium ; Tomography, Optical Coherence
    Language English
    Publishing date 2022-01-21
    Publishing country England
    Document type Letter
    ZDB-ID 2408333-1
    ISSN 1755-3768 ; 1755-375X
    ISSN (online) 1755-3768
    ISSN 1755-375X
    DOI 10.1111/aos.15087
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Voluntary Wheel Running in Old C57BL/6 Mice Reduces Age-Related Inflammation in the Colon but Not in the Brain.

    Ederer, Marie-Luise / Günther, Madlen / Best, Lena / Lindner, Julia / Kaleta, Christoph / Witte, Otto W / Simon, Rowena / Frahm, Christiane

    Cells

    2022  Volume 11, Issue 3

    Abstract: Inflammation is considered a possible cause of cognitive decline during aging. This study investigates the influence of physical activity and social isolation in old mice on their cognitive functions and inflammation. The Barnes maze task was performed ... ...

    Abstract Inflammation is considered a possible cause of cognitive decline during aging. This study investigates the influence of physical activity and social isolation in old mice on their cognitive functions and inflammation. The Barnes maze task was performed to assess spatial learning and memory in 3, 9, 15, 24, and 28 months old male C57BL/6 mice as well as following voluntary wheel running (VWR) and social isolation (SI) in 20 months old mice. Inflammatory gene expression was analyzed in hippocampal and colonic samples by qPCR. Cognitive decline occurs in mice between 15 and 24 months of age. VWR improved cognitive functions while SI had negative effects. Expression of inflammatory markers changed during aging in the hippocampus (
    MeSH term(s) Aging ; Animals ; Brain ; Colon ; Inflammation ; Male ; Mice ; Mice, Inbred C57BL ; Motor Activity
    Language English
    Publishing date 2022-02-06
    Publishing country Switzerland
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2661518-6
    ISSN 2073-4409 ; 2073-4409
    ISSN (online) 2073-4409
    ISSN 2073-4409
    DOI 10.3390/cells11030566
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Prolonged Lifetimes of Histologic Autofluorescence in Ectopic Retinal Pigment Epithelium in Age-Related Macular Degeneration.

    Simon, Rowena / Jentsch, Marius / Karimimousivandi, Parva / Cao, Dongfeng / Messinger, Jeffrey D / Meller, Daniel / Curcio, Christine A / Hammer, Martin

    Investigative ophthalmology & visual science

    2022  Volume 63, Issue 13, Page(s) 5

    Abstract: Purpose: The purpose of this study was to investigate histologic autofluorescence lifetimes and spectra of retinal pigment epithelium (RPE) on the transition from normal aging to RPE activation and migration in age-related macular degeneration (AMD).: ...

    Abstract Purpose: The purpose of this study was to investigate histologic autofluorescence lifetimes and spectra of retinal pigment epithelium (RPE) on the transition from normal aging to RPE activation and migration in age-related macular degeneration (AMD).
    Methods: Autofluorescence lifetimes and spectra of 9 donor eyes were analyzed in cryosections by means of 2-photon excited fluorescence at 960 nm. Spectra were detected at 483 to 665 nm. Lifetimes were measured using time-correlated single photon counting in 2 spectral channels: 500 to 550 nm (short-wavelength spectral channel [SSC]) and 550 to 700 nm (long-wavelength spectral channel [LSC]). Fluorescence decays over time were approximated by a series of three exponential functions. The amplitude-weighted mean fluorescence lifetime was determined. Markers for retinoid activity (RPE65) and immune function (CD68) were immunolocalized in selected neighboring sections.
    Results: We identified 9 RPE morphology phenotypes resulting in 399 regions of interest (ROIs) for spectral and 497 ROIs for lifetime measurements. RPE dysmorphia results in a shorter wavelength peak of spectral emission: normal aging versus RPE migrated into the retina (intraELM) = 601.7 (9.5) nm versus 581.6 (7.3) nm, P < 0.001, whereas autofluorescence lifetimes increase: normal aging versus intraELM: SSC 180 (44) picosecond (ps) versus 320 (86) ps, P < 0.001; and LSC 250 (55) ps versus 441 (76) ps, P < 0.001. Ectopic RPE within the neurosensory retina is strongly CD68 positive and RPE65 negative.
    Conclusions: In the process of RPE degeneration, comprising different steps of dysmorphia and migration, lengthening of autofluorescence lifetimes and a hypsochromic shift of emission spectra can be observed. These autofluorescence changes might provide early biomarkers for AMD progression and contribute to our understanding of RPE-driven pathology.
    MeSH term(s) Humans ; Retinal Pigment Epithelium/pathology ; Ophthalmoscopy/methods ; Macular Degeneration/diagnosis ; Macular Degeneration/pathology ; Retina/pathology ; Tomography, Optical Coherence/methods ; Fluorescein Angiography/methods
    Language English
    Publishing date 2022-12-05
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 391794-0
    ISSN 1552-5783 ; 0146-0404
    ISSN (online) 1552-5783
    ISSN 0146-0404
    DOI 10.1167/iovs.63.13.5
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Optic disc blood perfusion and oxygenation in glaucoma.

    Al Zoubi, Hosni / Riemer, Thomas / Simon, Rowena / Vilser, Walthard / Hasan, Somar / Meller, Daniel / Augsten, Regine / Hammer, Martin

    Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie

    2022  Volume 260, Issue 11, Page(s) 3587–3595

    Abstract: Purpose: To investigate the haemoglobin concentration and oxygenation in the optic disc in glaucoma patients vs. controls.: Methods: Thirty-one eyes of primary open angle glaucoma patients (mean age: 64.9 ± 2.1 years) and 31 eyes of 31 healthy ... ...

    Abstract Purpose: To investigate the haemoglobin concentration and oxygenation in the optic disc in glaucoma patients vs. controls.
    Methods: Thirty-one eyes of primary open angle glaucoma patients (mean age: 64.9 ± 2.1 years) and 31 eyes of 31 healthy controls (65.5 ± 2.0 years) were included. Perimetry, optical coherence tomography (OCT), and OCT angiography were performed. Multispectral imaging was used to record the optic disc reflectance at wavelengths 522 nm, 548 nm, 555 nm, 586 nm, and 610 nm, and haemoglobin concentration and oxygenation (SO
    Results: The haemoglobin concentration was significantly lower (p < 0.001) in the rim (40.0 ± 6.3) and the excavation (35.7 ± 8.0) of the glaucoma patients' discs than in controls (45.7 ± 7.5). SO
    Conclusions: The optic disc haemoglobin concentration and oxygenation are quantifiable from multispectral imaging and reduced in glaucoma. The correlation of haemoglobin concentration with perfusion density, RNFL thickness and visual field loss indicates its implication in glaucoma pathology.
    MeSH term(s) Humans ; Middle Aged ; Aged ; Optic Disk/pathology ; Glaucoma, Open-Angle/diagnosis ; Glaucoma, Open-Angle/pathology ; Nerve Fibers/pathology ; Retinal Ganglion Cells/pathology ; Glaucoma/pathology ; Visual Field Tests/methods ; Tomography, Optical Coherence/methods ; Hemoglobins ; Perfusion ; Intraocular Pressure
    Chemical Substances Hemoglobins
    Language English
    Publishing date 2022-06-06
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 8435-9
    ISSN 1435-702X ; 0721-832X
    ISSN (online) 1435-702X
    ISSN 0721-832X
    DOI 10.1007/s00417-022-05722-6
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Changes in drusen-associated autofluorescence over time observed by fluorescence lifetime imaging ophthalmoscopy in age-related macular degeneration.

    Schwanengel, Linda-Sophia / Weber, Sebastian / Simon, Rowena / Lehmann, Thomas / Augsten, Regine / Meller, Daniel / Hammer, Martin

    Acta ophthalmologica

    2022  Volume 101, Issue 2, Page(s) e154–e166

    Abstract: Purpose: To observe fundus autofluorescence (FAF) lifetimes and peak emission wavelength (PEW) of drusen with respect to the pathology of the overlying RPE in the follow-up of AMD-patients.: Methods: Forty eyes of 38 patients (age: 75.1 ± 7.1 years) ... ...

    Abstract Purpose: To observe fundus autofluorescence (FAF) lifetimes and peak emission wavelength (PEW) of drusen with respect to the pathology of the overlying RPE in the follow-up of AMD-patients.
    Methods: Forty eyes of 38 patients (age: 75.1 ± 7.1 years) with intermediate AMD were included. FAF lifetimes and PEW were recorded by fluorescence lifetime imaging ophthalmoscopy (FLIO). Twenty-six eyes had a follow-up investigation between months 12 and 36, and 10 at months 37-72. AMD progression was retrieved from color fundus photography (CFP) and OCT. Drusen were classified with respect to changes in the overlying RPE into groups no, questionable or faint, and apparent hyperpigmentation based on CFP.
    Results: Among the 210 hyperautofluorescent drusen found at baseline, those with hyperpigmentation had longer lifetimes and shorter PEW than those without. Drusen without hyperpigmentation had shorter lifetimes and PEW than neighboring RPE (all p < 0.001) at baseline, but drusen lifetimes increased, and PEW shortened further over follow-up. Eyes, showing AMD progression, had significantly longer FAF lifetimes at baseline than non-progressing eyes: 282 ± 102 ps versus 245 ± 98 ps, p < 0.001 and 365 ± 44 ps vs. 336 ± 48 ps, p = 0.025 for short and long wavelength FLIO channel, respectively.
    Conclusions: Depending on hyperpigmentation properties, drusen show lifetimes and PEW different from that of adjacent RPE which change over the natural history of AMD. This difference and change, however, might reflect progressive dysmorphia of the RPE rather than representing fluorescence of drusen material itself. Nevertheless, the observed FAF changes could make FLIO a useful tool for the early detection of AMD progression risk.
    MeSH term(s) Humans ; Aged ; Aged, 80 and over ; Fluorescein Angiography/methods ; Retina/pathology ; Macular Degeneration/diagnosis ; Macular Degeneration/pathology ; Ophthalmoscopy/methods ; Fundus Oculi ; Tomography, Optical Coherence/methods ; Retinal Drusen/diagnosis
    Language English
    Publishing date 2022-08-26
    Publishing country England
    Document type Journal Article
    ZDB-ID 2408333-1
    ISSN 1755-3768 ; 1755-375X
    ISSN (online) 1755-3768
    ISSN 1755-375X
    DOI 10.1111/aos.15238
    Database MEDical Literature Analysis and Retrieval System OnLINE

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