Thomas Ach

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PURPOSE Lipofuscin (LF) accumulation within RPE cells is considered pathogenic in AMD. To test whether LF contributes to RPE cell loss in aging and to provide a cellular basis for fundus autofluorescence (AF) we created maps of human RPE cell number and histologic AF. METHODS Retinal pigment epithelium-Bruch's membrane flat mounts were prepared from 20(More)
PURPOSE Lipofuscin (LF) and melanolipofuscin (MLF) of the retinal pigment epithelium (RPE) are the principal sources of autofluorescence (AF) signals in clinical fundus-AF imaging. Few details about the subcellular distribution of AF organelles in AMD are available. We describe the impact of aging and AMD on RPE morphology revealed by the distribution of AF(More)
PURPOSE To seek pathways of retinal pigment epithelium (RPE) fate in age-related macular degeneration via a morphology grading system; provide nomenclature, visualization targets, and metrics for clinical imaging and model systems. METHODS Donor eyes with geographic atrophy (GA) or choroidal neovascularization (CNV) and one GA eye with previous clinical(More)
PURPOSE To describe, illustrate, and account for two cell types plausibly derived from RPE in geographic atrophy (GA) and choroidal neovascularization (CNV) of AMD, using melanosomes, lipofuscin, and basal laminar deposit (BLamD) as anatomical markers. METHODS Human donor eyes with GA (n = 13) or CNV (n = 39) were histologically processed,(More)
Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) have been reported in patients with aquaporin-4 antibody (AQP4-IgG)-negative neuromyelitis optica spectrum disorders (NMOSD). The objective of this study was to describe optic neuritis (ON)-induced neuro-axonal damage in the retina of MOG-IgG-positive patients in comparison with(More)
BACKGROUND The human retinal pigment epithelium (RPE) is reportedly 3% bi-nucleated. The importance to human vision of multi-nucleated (MN)-RPE cells could be clarified with more data about their distribution in central retina. METHODS Nineteen human RPE-flatmounts (9 ≤ 51 years, 10 > 80 years) were imaged at 12 locations: 3 eccentricities (fovea,(More)
PURPOSE To assess outer retinal tubulation (ORT) morphology from spectral-domain optical coherence tomography (SD-OCT) volumes and donor eye histology, analyze ORT reflectivity, and estimate the number of cones surviving in ORT. METHODS In SD-OCT volumes from nine patients with advanced AMD, ORT was analyzed en face and in B-scans. The hyperreflective ORT(More)
This article presents a case of acute bilateral impaired vision and central scotoma in an 11-year-old boy. Looking directly into a laser beam of a laser pointer for only a few seconds can cause retinal damage in the form of lesions of the retinal pigment epithelium and the photoreceptor layer, up to retinal hemorrhage. Patients often complain about impaired(More)
PURPOSE Discovery of candidate spectra for abundant fluorophore families in human retinal pigment epithelium (RPE) by ex vivo hyperspectral imaging. METHODS Hyperspectral autofluorescence emission images were captured between 420 and 720 nm (10-nm intervals), at two excitation bands (436-460, 480-510 nm), from three locations (fovea, perifovea,(More)
Upon excitation with different wavelengths of light, biological tissues emit distinct but related autofluorescence signals. We used non-negative matrix factorization (NMF) to simultaneously decompose co-registered hyperspectral emission data from human retinal pigment epithelium/Bruch's membrane specimens illuminated with 436 and 480 nm light. NMF analysis(More)
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