Thomas Ach1, Carrie Huisingh1, Gerald McGwin2, Jeffrey D Messinger1, Tianjiao Zhang1, Mark J Bentley3, Danielle B Gutierrez4, Zsolt Ablonczy5, R Theodore Smith6, Kenneth R Sloan3, Christine A Curcio1. 1. University of Alabama at Birmingham, Department of Ophthalmology, Birmingham, Alabama, United States. 2. University of Alabama at Birmingham, Department of Ophthalmology, Birmingham, Alabama, United States University of Alabama at Birmingham, Department of Epidemiology, Birmingham, Alabama, United States. 3. University of Alabama at Birmingham, Department of Computer and Information Sciences, Birmingham, Alabama, United States. 4. Center for Coastal Studies, Texas A&M University-Corpus Christi, Corpus Christi, Texas, United States. 5. Medical University of South Carolina, Department of Ophthalmology, Charleston, South Carolina, United States. 6. New York University School of Medicine, Department of Ophthalmology, New York, New York, United States.
Abstract
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 donor eyes (10 ≤ 51 and 10 > 80 years; postmortem: ≤4.2 hours; no retinal pathologies), preserving foveal position. Phalloidin-binding RPE cytoskeleton and LF-AF (488-nm excitation) were imaged at up to 90 predefined positions. Maps were assembled from 83,330 cells in 1470 locations. From Voronoi regions representing each cell, the number of neighbors, cell area, and total AF intensity normalized to an AF standard was determined. RESULTS: Highly variable between individuals, RPE-AF increases significantly with age. A perifoveal ring of high AF mirrors rod photoreceptor topography and fundus-AF. Retinal pigment epithelium cell density peaks at the fovea, independent of age, yet no net RPE cell loss is detectable. The RPE monolayer undergoes considerable lifelong re-modeling. The relationship of cell size and AF, a surrogate for LF concentration, is orderly and linear in both groups. Autofluorescence topography differs distinctly from the topography of age-related rod loss. CONCLUSIONS: Digital maps of quantitative AF, cell density, and packing geometry provide metrics for cellular-resolution clinical imaging and model systems. The uncoupling of RPE LF content, cell number, and photoreceptor topography in aging challenges LF's role in AMD. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
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 donor eyes (10 ≤ 51 and 10 > 80 years; postmortem: ≤4.2 hours; no retinal pathologies), preserving foveal position. Phalloidin-binding RPE cytoskeleton and LF-AF (488-nm excitation) were imaged at up to 90 predefined positions. Maps were assembled from 83,330 cells in 1470 locations. From Voronoi regions representing each cell, the number of neighbors, cell area, and total AF intensity normalized to an AF standard was determined. RESULTS: Highly variable between individuals, RPE-AF increases significantly with age. A perifoveal ring of high AF mirrors rod photoreceptor topography and fundus-AF. Retinal pigment epithelium cell density peaks at the fovea, independent of age, yet no net RPE cell loss is detectable. The RPE monolayer undergoes considerable lifelong re-modeling. The relationship of cell size and AF, a surrogate for LF concentration, is orderly and linear in both groups. Autofluorescence topography differs distinctly from the topography of age-related rod loss. CONCLUSIONS: Digital maps of quantitative AF, cell density, and packing geometry provide metrics for cellular-resolution clinical imaging and model systems. The uncoupling of RPE LF content, cell number, and photoreceptor topography in aging challenges LF's role in AMD. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
Authors: Gregory R Jackson; Ingrid U Scott; Ivana K Kim; David A Quillen; Alessandro Iannaccone; John G Edwards Journal: Invest Ophthalmol Vis Sci Date: 2014-03-10 Impact factor: 4.799
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Authors: Chandrakumar Balaratnasingam; Jeffrey D Messinger; Kenneth R Sloan; Lawrence A Yannuzzi; K Bailey Freund; Christine A Curcio Journal: Ophthalmology Date: 2017-01-30 Impact factor: 12.079
Authors: R Theodore Smith; Robert Post; Ansh Johri; Michele D Lee; Zsolt Ablonczy; Christine A Curcio; Thomas Ach; Paul Sajda Journal: Biomed Opt Express Date: 2014-11-06 Impact factor: 3.732