@article{TarauBerlinCurcioetal.2019,
  author    = {Tarau, Ioana-Sandra and Berlin, Andreas and Curcio, Christine A. and Ach, Thomas},
  title     = {The cytoskeleton of the retinal pigment epithelium: from normal aging to age-related macular degeneration},
  series = {International Journal of Molecular Science},
  volume    = {20},
  journal   = {International Journal of Molecular Science},
  number    = {14},
  issn      = {1422-0067},
  doi       = {10.3390/ijms20143578},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201781},
  year      = {2019},
  abstract  = {The retinal pigment epithelium (RPE) is a unique epithelium, with major roles which are essential in the visual cycle and homeostasis of the outer retina. The RPE is a monolayer of polygonal and pigmented cells strategically placed between the neuroretina and Bruch membrane, adjacent to the fenestrated capillaries of the choriocapillaris. It shows strong apical (towards photoreceptors) to basal/basolateral (towards Bruch membrane) polarization. Multiple functions are bound to a complex structure of highly organized and polarized intracellular components: the cytoskeleton. A strong connection between the intracellular cytoskeleton and extracellular matrix is indispensable to maintaining the function of the RPE and thus, the photoreceptors. Impairments of these intracellular structures and the regular architecture they maintain often result in a disrupted cytoskeleton, which can be found in many retinal diseases, including age-related macular degeneration (AMD). This review article will give an overview of current knowledge on the molecules and proteins involved in cytoskeleton formation in cells, including RPE and how the cytoskeleton is affected under stress conditions — especially in AMD.},
  language  = {en}
}
@article{LittsAchHammacketal.2016,
  author    = {Litts, Katie M. and Ach, Thomas and Hammack, Kristen M. and Sloan, Kenneth R. and Zhang, Yuhua and Freund, K. Bailey and Curcio, Christine A.},
  title     = {Quantitative Analysis of Outer Retinal Tubulation in Age-Related Macular Degeneration From Spectral-Domain Optical Coherence Tomography and Histology},
  series = {Investigative Ophthalmology \& Visual Science},
  volume    = {57},
  journal   = {Investigative Ophthalmology \& Visual Science},
  doi       = {10.1167/iovs.16-19262},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165532},
  pages     = {2647-2656},
  year      = {2016},
  abstract  = {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 border in cross-section was delineated and surface area calculated. Reflectivity was compared between ORT types (Closed, Open, Forming, and Branching). A flatmount retina from a donor with neovascular AMD was labeled to visualize the external limiting membrane that delimits ORT and allow measurements of cross-sectional cone area, center-to-center cone spacing, and cone density. The number of cones surviving in ORT was estimated. Results: By en face SD-OCT, ORT varies in complexity and shape. Outer retinal tubulation networks almost always contain Closed cross-sections. Spectral-domain OCT volumes containing almost exclusively Closed ORTs showed no significant direction-dependent differences in hyperreflective ORT border intensity. The surface areas of partial ORT assessed by SD-OCT volumes ranged from 0.16 to 1.76 mm2. From the flatmount retina, the average cross-sectional area of cone inner segments was 49.1 ± 7.9 μm2. The average cone spacing was 7.5 ± 0.6 μm. Outer retinal tubulation cone density was 20,351 cones/mm2. The estimated number of cones in ORT in a macula ranged from 26,399 to 186,833 cones, which is 6\% to 44\% of the cones present in a healthy macula. Conclusions: These first estimates for cone density and number of cones surviving in ORT suggest that ORT formation considerably distorts the photoreceptor mosaic. Results provide additional insight into the reflectivity characteristics and number of ORT cones observable in living patients by SD-OCT, as cones persist and disease progresses.},
  language  = {en}
}
@article{BenAmiTongBhuiyanetal.2016,
  author    = {Ben Ami, Tal and Tong, Yuehong and Bhuiyan, Alauddin and Huisingh, Carrie and Ablonczy, Zsolt and Ach, Thomas and Curcio, Christine A. and Smith, R. Theodore},
  title     = {Spatial and Spectral Characterization of Human Retinal Pigment Epithelium Fluorophore Families by Ex Vivo Hyperspectral Autofluorescence Imaging},
  series = {Translational Vision Science \& Technology},
  volume    = {5},
  journal   = {Translational Vision Science \& Technology},
  number    = {3},
  doi       = {10.1167/tvst.5.3.5},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168328},
  pages     = {5},
  year      = {2016},
  abstract  = {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, near-periphery) in 20 normal RPE/Bruch's membrane (BrM) flatmounts. Mathematical factorization extracted a BrM spectrum (S0) and abundant lipofuscin/melanolipofuscin (LF/ML) spectra of RPE origin (S1, S2, S3) from each tissue. Results: Smooth spectra S1 to S3, with perinuclear localization consistent with LF/ML at all three retinal locations and both excitations in 14 eyes (84 datasets), were included in the analysis. The mean peak emissions of S0, S1, and S2 at λ\(_{ex}\) 436 nm were, respectively, 495 ± 14, 535 ± 17, and 576 ± 20 nm. S3 was generally trimodal, with peaks at either 580, 620, or 650 nm (peak mode, 650 nm). At λ\(_{ex}\) 480 nm, S0, S1, and S2 were red-shifted to 526 ± 9, 553 ± 10, and 588 ± 23 nm, and S3 was again trimodal (peak mode, 620 nm). S1 often split into two spectra, S1A and S1B. S3 strongly colocalized with melanin. There were no significant differences across age, sex, or retinal location. Conclusions: There appear to be at least three families of abundant RPE fluorophores that are ubiquitous across age, retinal location, and sex in this sample of healthy eyes. Further molecular characterization by imaging mass spectrometry and localization via super-resolution microscopy should elucidate normal and abnormal RPE physiology involving fluorophores. Translational Relevance: Our results help establish hyperspectral autofluorescence imaging of the human retinal pigment epithelium as a useful tool for investigating retinal health and disease.},
  language  = {en}
}