Ophthalmology Commons^™

Swelling And Eicosanoid Metabolites Differentially Gate Trpv4 Channels In Retinal Neurons And Glia., Daniel A. Ryskamp, Andrew O. Jo, Amber M M. Frye, Felix Vazquez-Chona, Nanna Macaulay, Wallace B. Thoreson, David Križaj

Journal Articles: Ophthalmology

Activity-dependent shifts in ionic concentrations and water that accompany neuronal and glial activity can generate osmotic forces with biological consequences for brain physiology. Active regulation of osmotic gradients and cellular volume requires volume-sensitive ion channels. In the vertebrate retina, critical support to volume regulation is provided by Müller astroglia, but the identity of their osmosensor is unknown. Here, we identify TRPV4 channels as transducers of mouse Müller cell volume increases into physiological responses. Hypotonic stimuli induced sustained [Ca(2+)]i elevations that were inhibited by TRPV4 antagonists and absent in TRPV4(-/-) Müller cells. Glial TRPV4 signals were phospholipase A2- and cytochrome P450-dependent, …

Fundus Autofluorescence Imaging: Fundamentals And Clinical Relevance., Yasir J. Sepah, Abeer Akhtar, Mohammad Ali Sadiq, Yamama Hafeez, Humzah Nasir, Brian Perez, Narissa Mawji, Diana J. Dean, Daniel Ferraz, Quan Dong Nguyen

Journal Articles: Ophthalmology

Fundus autofluorescence (FAF), a relatively new imaging modality, focuses on the fluorescent properties of pigments in the retina to generate images that help us view various disease processes from a different perspective. It aids us in the understanding of the pathophysiology of different retinal disorders. Recently, FAF imaging is being used commonly to help us in the diagnosis, prognosis as well as in determining the treatment response of various retinal disorders. It generates an image based on the distribution pattern of a fluorescent pigment called lipofuscin. Knowing the distribution pattern of lipofuscin in the normal retina is key to understanding …

Retina-Simulating Phantom For Optical Coherence Tomography., Jigesh Baxi, William Calhoun, Yasir Jamal Sepah, Daniel X. Hammer, Ilko Ilev, T. Joshua Pfefer, Quan Dong Nguyen, Anant Agrawal

Journal Articles: Ophthalmology

Optical coherence tomography (OCT) is a rapidly growing imaging modality, particularly in the field of ophthalmology. Accurate early diagnosis of diseases requires consistent and validated imaging performance. In contrast to more well-established medical imaging modalities, no standardized test methods currently exist for OCT quality assurance. We developed a retinal phantom which mimics the thickness and near-infrared optical properties of each anatomical retinal layer as well as the surface topography of the foveal pit. The fabrication process involves layer-by-layer spin coating of nanoparticle-embedded silicone films followed by laser micro-etching to modify the surface topography. The thickness of each layer and dimensions …

Complement Expression In The Retina Is Not Influenced By Short-Term Pressure Elevation, Konstantin Astafurov, Cecilia Q. Dong, Lampros Panagis, Gautam Kamtham, Lizhen Ren, Anna Rozenboym, Tarique D. Perera, Jeremy D. Coplan, John Danias

Publications and Research

Purpose: To determine whether short-term pressure elevation affects complement gene expression in the retina in vitro and in vivo.

Methods: Muller cell (TR-MUL5) cultures and organotypic retinal cultures from adult mice and monkeys were sub- jected to either 24-h or 72-h of pressure at 0, 15, 30, and 45 mmHg above ambient. C57BL/6 mice were subjected to microbead-induced intraocular pressure (IOP) elevation for 7 days. RNA and protein were extracted and used for analysis of expression levels of complement component genes and complement component 1, q subcomponent (C1q) and comple- ment factor H (CFH) immunoblotting. …