Search

Your search keyword '"Markolf H. Niemz"' showing total 2 results
Start Over Author "Markolf H. Niemz" Journal journal of biomedical optics
2 results on '"Markolf H. Niemz"'

1. Two-photon excited autofluorescence imaging of human retinal pigment epithelial cells

Author

Günter Giese, Sarah Rebecca Snyder, Markolf H. Niemz, Mikael Agopov, Josef F. Bille, Almut Bindewald-Wittich, Olivier La Schiazza, Meng Han, Hui Sun, Frank G. Holz, and Jiayi Yu

Subjects
Adult, Biomedical Engineering, In Vitro Techniques, Lipofuscin, law.invention, Biomaterials, Pigment, chemistry.chemical_compound, Two-photon excitation microscopy, Confocal microscopy, law, Cadaver, medicine, Humans, Pigment Epithelium of Eye, Aged, 80 and over, Retina, Luminescent Agents, Microscopy, Confocal, Chemistry, Retinal, Anatomy, Middle Aged, eye diseases, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Cell biology, Autofluorescence, Microscopy, Fluorescence, Multiphoton, medicine.anatomical_structure, Cytoplasm, visual_art, visual_art.visual_art_medium, sense organs
Abstract

Degeneration of retinal pigment epithelial (RPE) cells severely impairs the visual function of retina photoreceptors. However, little is known about the events that trigger the death of RPE cells at the subcellular level. Two-photon excited autofluorescence (TPEF) imaging of RPE cells proves to be well suited to investigate both the morphological and the spectral characteristics of the human RPE cells. The dominant fluorophores of autofluorescence derive from lipofuscin (LF) granules that accumulate in the cytoplasm of the RPE cells with increasing age. Spectral TPEF imaging reveals the existence of abnormal LF granules with blue shifted autofluorescence in RPE cells of aging patients and brings new insights into the complicated composition of the LF granules. Based on a proposed two-photon laser scanning ophthalmoscope, TPEF imaging of the living retina may be valuable for diagnostic and pathological studies of age related eye diseases.

Published
2006
Full Text
View/download PDF

2. Age-related structural abnormalities in the human retina-choroid complex revealed by two-photon excited autofluorescence imaging.

Author

Meng Han, Guenter Giese, Steffen Schmitz-Valckenberg, Almut Bindewald-Wittich, Frank G. Holz, Jiayi Yu, Josef F. Bille, and Markolf H. Niemz

Subjects
BIOCHEMISTRY, RETINOIDS, RETINAL degeneration, MEDICAL imaging systems
Abstract

The intensive metabolism of photoreceptors is delicately maintained by the retinal pigment epithelium (RPE) and the choroid. Dysfunction of either the RPE or choroid may lead to severe damage to the retina. Two-photon excited autofluorescence (TPEF) from endogenous fluorophores in the human retina provides a novel opportunity to reveal age-related structural abnormalities in the retina-choroid complex prior to apparent pathological manifestations of age-related retinal diseases. In the photoreceptor layer, the regularity of the macular photoreceptor mosaic is preserved during aging. In the RPE, enlarged lipofuscin granules demonstrate significantly blue-shifted autofluorescence, which coincides with the depletion of melanin pigments. Prominent fibrillar structures in elderly Bruch’s membrane and choriocapillaries represent choroidal structure and permeability alterations. Requiring neither slicing nor labeling, TPEF imaging is an elegant and highly efficient tool to delineate the thick, fragile, and opaque retina-choroid complex, and may provide clues to the trigger events of age-related macular degeneration. [ABSTRACT FROM AUTHOR]

Published
2007
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results