Ophthalmology Commons^™

Neural Reprogramming In Retinal Degeneration, Robert E Marc, Bryan W Jones, James R Anderson, Krista Kinard, David W Marshak, John H Wilson, Theodore Wensel, Robert J Lucas

Faculty, Staff and Student Publications

PURPOSE: Early visual defects in degenerative diseases such as retinitis pigmentosa (RP) may arise from phased remodeling of the neural retina. The authors sought to explore the functional expression of ionotropic (iGluR) and group 3, type 6 metabotropic (mGluR6) glutamate receptors in late-stage photoreceptor degeneration.

METHODS: Excitation mapping with organic cations and computational molecular phenotyping were used to determine whether retinal neurons displayed functional glutamate receptor signaling in rodent models of retinal degeneration and a sample of human RP.

RESULTS: After photoreceptor loss in rodent models of RP, bipolar cells lose mGluR6 and iGluR glutamate-activated currents, whereas amacrine and ganglion …

Nasal Airflow And Odorant Transport Modeling In Patients With Chronic Rhinosimusitis, Kai Zhao, Beverly J. Cowart, N. E. Rawson, Peter W. Scherer, K. T. Clock, A. A. Vainius, Pamela Dalton, Edward Pribitkin, David Rosen

Department of Otolaryngology - Head and Neck Surgery Faculty Papers

Poster presentation at Association for Chemoreception Sciences (ACHEMS) in Sarasota Florida April 25-29, 2007.

Introduction:

Our on-going clinical project aims to quantify the conductive mechanism contributing toolfactory loss in chronic rhinosinusitis (CRS) patients, in addition to other inflammatory causes(see Yee, et al, 200 and Feng, et al, 203). CRS, a common disease affecting 32 millionAmericans annually, is reportedly associated with at least 15% of all olfactory losses. Airwayconstriction as a result of inflammation or the presence of polyps may limit odor access to thereceptor sites and lead to olfactory dysfunction. As yet, the functional impact of various nasalobstructions as sequelae …

Postoperative Wound Leak And Anterior Chamber Reaction In Patients Undergoing Phacoemulsification Cataract Surgery With Sutured And Sutureless Corneal Incisions, Tanveer Anjum Chaudhry, Muhammad Shahzad Shamim, Sameer Khan, Khabir Ahmad

Department of Surgery Docs

Purpose: To compare the rates of significant post operative wound leak and anterior chamber (AC) reaction in patients undergoing phacoemulsification cataract surgery with sutured and sutureless corneal incisions. Material and Methods: All eyes scheduled to have phacoemulsification surgery by two surgeons at two centers were selected. The first group of eyes underwent phacoemulsification surgery with 3.25 mm superior and superior-temporal clear corneal incisions. The incision was sutured using a single 10/0 nylon suture. The second group of eyes underwent an identical surgery, but the incision was not sutured. Patients were followed up at 24 hours, and 1 week and evaluated …

Effects Of Curcumin On Retinal Oxidative Stress And Inflammation In Diabetes, Renu A. Kowluru, Mamta Kanwar

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Oxidative stress and inflammation are implicated in the pathogenesis of retinopathy in diabetes. The aim of this study is to examine the effect of curcumin, a polyphenol with antioxidant and anti-inflammatory properties, on diabetes-induced oxidative stress and inflammation in the retina of rats.

Methods

A group of streptozotocin-induced diabetic rats received powdered diet supplemented with 0.05% curcumin (w/w), and another group received diet without curcumin. The diets were initiated soon after induction of diabetes, and the rats were sacrificed 6 weeks after induction of diabetes. The retina was used to quantify oxidative stress and pro-inflammatory markers.

Results

Antioxidant …

Patient Education In Glaucoma: What Do Patients Know About Glaucoma?, Vital Paulino Costa, George L Spaeth, Maura Smith, Cordelia Uddoh, José Paulo Cabral Vasconcellos, Newton Kara-José

Wills Eye Hospital Papers

PURPOSE: To evaluate the knowledge glaucoma patients have about their disease and its treatment.

METHODS: One hundred and eighty-three patients were interviewed at the Glaucoma Service of Wills Eye Hospital (Philadelphia, USA, Group 1) and 100 at the Glaucoma Service of University of Campinas (Campinas, Brazil, Group 2). An informal, relaxed atmosphere was created by the interviewer before asking a list of 18 open-ended questions.

RESULTS: In Group 1, 44% of the 183 patients did not have an acceptable idea about what glaucoma is, 30% did not know the purpose of the medications they were taking, 47% were not aware …

Malignant Melanoma Metastacizing To The Thyroid Gland: A Case Report And Review Of The Literature, Brian Kung, Saba Aftab, Moira Wood, David Rosen

Department of Otolaryngology - Head and Neck Surgery Faculty Papers

Oral presentation 2006 AAO-H&NS Annual Meeting

Toronto, Canada September 17-20, 2006.

Objectives: The thyroid gland is a relatively uncommon site for secondary malignancy. Even lesscommon is metastasis of malignant melanoma to the thyroid gland. We present a case of malignantmelanoma metastatic to the thyroid gland presenting as thyroid enlargement.

Study Design: This is a case report which utilizes chart review, intraoperative photographs,radiographic images, and pathology slides.

Methods: A 68 year old patient with no prior evidence of primary skin melanoma presented witha neck mass which tested positive for melanoma. A year and a half following modified radical neckdissection, the patient …

Loss Of Sparc-Mediated Vegfr-1 Suppression After Injury Reveals A Novel Antiangiogenic Activity Of Vegf-A, Miho Nozaki, Eiji Sakurai, Brian J. Raisler, Judit Z. Baffi, Jassir Witta, Yuichiro Ogura, Rolf A. Brekken, E Helene Sage, Balamurali K. Ambati, Jayakrishna Ambati

Ophthalmology and Visual Science Faculty Publications

VEGF-A promotes angiogenesis in many tissues. Here we report that choroidal neovascularization (CNV) incited by injury was increased by excess VEGF-A before injury but was suppressed by VEGF-A after injury. This unorthodox antiangiogenic effect was mediated via VEGFR-1 activation and VEGFR-2 deactivation, the latter via Src homology domain 2-containing (SH2-containing) tyrosine phosphatase-1 (SHP-1). The VEGFR-1-specific ligand placental growth factor-1 (PlGF-1), but not VEGF-E, which selectively binds VEGFR-2, mimicked these responses. Excess VEGF-A increased CNV before injury because VEGFR-1 activation was silenced by secreted protein, acidic and rich in cysteine (SPARC). The transient decline of SPARC after injury revealed a temporal …

First Report Of Ophthalmomyaisis Externa In Pakistan, Azam Ali, Agha Hassan Feroze, Paul Ferrar, Asad Abbas, Mohammad Asim Beg

Section of Ophthalmology

Two individuals presented to the Aga Khan University Opthalmology service with foreign-body sensation, pain and redness in one of their eyes. Slit-lamp biomicroscopy revealed tiny larvae crawling around the conjunctival sac. They were mechanically removed under topical anaesthesia and preserved for light microscopy and photography. Comprehensive liaison was established with the Australian Centre for International Agriculture Research for identification of these larvae. Their morphology characterized them as members of fruit-fly, Oestridae family. At least one of them was positively identified as first instar larva of Oestrus ovis. This report describes the first instance of such infections in Southern Pakistan, as …

Stromal Haze, Myofibroblasts, And Surface Irregularity After Prk, Marcelo V. Netto, Rajiv R. Mohan, Sunilima Sinha, Ajay Sharma, William Dupps, Steven E. Wilson

Pharmacy Faculty Articles and Research

The aim of this study was to investigate the relationship between the level of stromal surface irregularity after photorefractive keratectomy (PRK) and myofibroblast generation along with the development of corneal haze.

Variable levels of stromal surface irregularity were generated in rabbit corneas by positioning a fine mesh screen in the path of excimer laser during ablation for a variable percentage of the terminal pulses of the treatment for myopia that does not otherwise generate significant opacity. Ninety-six rabbits were divided into eight groups[.]

Slit lamp analysis and haze grading were performed in all groups. Rabbits were sacrificed at 4 hr …

Paired-Pulse Depression At Photoreceptor Synapses., Katalin Rabl, Lucia Cadetti, Wallace B. Thoreson

Journal Articles: Ophthalmology

Synaptic depression produced by repetitive stimulation is likely to be particularly important in shaping responses of second-order retinal neurons at the tonically active photoreceptor synapse. We analyzed the time course and mechanisms of synaptic depression at rod and cone synapses using paired-pulse protocols involving two complementary measurements of exocytosis: (1) paired whole-cell recordings of the postsynaptic current (PSC) in second-order retinal neurons and (2) capacitance measurements of vesicular membrane fusion in rods and cones. PSCs in ON bipolar, OFF bipolar, and horizontal cells evoked by stimulation of either rods or cones recovered from paired-pulse depression (PPD) at rates similar to …

Effect Of Prophylactic And Therapeutic Mitomycin C On Corneal Apoptosis, Cellular Proliferation, Haze, And Long-Term Keratocyte Density In Rabbits, Marcelo V. Netto, Rajiv R. Mohan, Sunilima Sinha, Ajay Sharma, Pankaj C. Gupta, Steven E. Wilson

Pharmacy Faculty Articles and Research

PURPOSE—To determine the mechanism through which topical mitomycin C prevents and treats corneal haze after photorefractive keratectomy (PRK) and to examine the effects of dosage and duration of exposure.

METHODS—In 224 New Zealand rabbits, −9.0 diopter PRK with mitomycin C or balanced salt solution was performed. Haze level was graded at the slit-lamp. Rabbits were sacrificed at 4 hours, 24 hours, 4 weeks, or 6 months after surgery and immunohistochemistry was performed with TUNEL assay, Ki67 and α-SMA.

RESULTS—TUNEL-positive apoptotic cells marginally increased in all mitomycin C groups whereas Ki67-positive mitotic cells decreased significantly following mitomycin C application. A greater …

When Red Lights Look Yellow, Joanne M. Wood, David A. Atchison, Alex Chaparro

Publications

Purpose. Red signals are typically used to signify danger. This study was conducted to investigate a situation identified by train drivers in which red signals appear yellow when viewed at long distances (∼900 m) through progressive-addition lenses.

Methods. A laboratory study was conducted to investigate the effects of defocus, target size, ambient illumination, and surround characteristics on the extent of the color misperception of train signals by nine visually normal participants. The data from the laboratory study were validated in a field study by measuring the amounts of defocus and the distances at which the misperception of the color of …

Kinetics Of Exocytosis Is Faster In Cones Than In Rods., Katalin Rabl, Lucia Cadetti, Wallace B. Thoreson

Journal Articles: Ophthalmology

Cone-driven responses of second-order retinal neurons are considerably faster than rod-driven responses. We examined whether differences in the kinetics of synaptic transmitter release from rods and cones may contribute to differences in postsynaptic response kinetics. Exocytosis from rods and cones was triggered by membrane depolarization and monitored in two ways: (1) by measuring EPSCs evoked in second-order neurons by depolarizing steps applied to presynaptic rods or cones during simultaneous paired whole-cell recordings or (2) by direct measurements of exocytotic increases in membrane capacitance. The kinetics of release was assessed by varying the length of the depolarizing test step. Both measures …

Palm Is Expressed In Both Developing And Adult Mouse Lens And Retina., Meryl Castellini, Louise V Wolf, Bharesh K Chauhan, Deni S Galileo, Manfred W Kilimann, Ales Cvekl, Melinda K Duncan

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Paralemmin (Palm) is a prenyl-palmitoyl anchored membrane protein that can drive membrane and process formation in neurons. Earlier studies have shown brain preferred Palm expression, although this protein is a major water insoluble protein in chicken lens fiber cells and the Palm gene may be regulated by Pax6. METHODS: The expression profile of Palm protein in the embryonic, newborn and adult mouse eye as well as dissociated retinal neurons was determined by confocal immunofluorescence. The relative mRNA levels of Palm, Palmdelphin (PalmD) and paralemmin2 (Palm2) in the lens and retina were determined by real time rt-PCR. RESULTS: In the …

Genetic Networks Controlling Retinal Injury, Felix R Vazquez-Chona, Amna N Khan, Chun K Chan, Anthony N Moore, Pramod K Dash, M Rosario Hernandez, Lu Lu, Elissa J Chesler, Kenneth F Manly, Robert W Williams, Eldon E Geisert

Faculty, Staff and Student Publications

PURPOSE: The present study defines genomic loci underlying coordinate changes in gene expression following retinal injury.

METHODS: A group of acute phase genes expressed in diverse nervous system tissues was defined by combining microarray results from injury studies from rat retina, brain, and spinal cord. Genomic loci regulating the brain expression of acute phase genes were identified using a panel of BXD recombinant inbred (RI) mouse strains. Candidate upstream regulators within a locus were defined using single nucleotide polymorphism databases and promoter motif databases.

RESULTS: The acute phase response of rat retina, brain, and spinal cord was dominated by transcription …

Chloride Equilibrium Potential In Salamander Cones., Wallace B. Thoreson, Eric J. Bryson

Journal Articles: Ophthalmology

BACKGROUND: GABAergic inhibition and effects of intracellular chloride ions on calcium channel activity have been proposed to regulate neurotransmission from photoreceptors. To assess the impact of these and other chloride-dependent mechanisms on release from cones, the chloride equilibrium potential (ECl) was determined in red-sensitive, large single cones from the tiger salamander retinal slice.

RESULTS: Whole cell recordings were done using gramicidin perforated patch techniques to maintain endogenous Cl- levels. Membrane potentials were corrected for liquid junction potentials. Cone resting potentials were found to average -46 mV. To measure ECl, we applied long depolarizing steps to activate the calcium-activated chloride current …

Method Of Inhibiting Alu Rna And Therapeutic Uses Thereof, Jayakrishna Ambati

Ophthalmology and Visual Science Faculty Patents

The presently-disclosed subject matter includes methods of identifying an Alu RNA inhibitor, and methods and compo sitions for inhibiting Alu RNA. Methods and compositions can be used for the treatment of geographic atrophy and other conditions of interest.

Unilateral Olfactory Thresholds In A Chemosensory Clinic Population, Beverly Cowart, Edmund Pribitkin, David Rosen, Christopher Klock, Timothy Laflam

Department of Otolaryngology - Head and Neck Surgery Faculty Papers

Poster presentation at 26th Annual Meeting of the Association of Chemoreception Sciences in Sarasota Florida, April 21-25, 2004.

INTRODUCTION

Because there is the possibility of unilateral loss of olfactory function or differential degrees of olfactory dysfunction in the two nostrils, unilateral tests of olfactory threshold sensitivity are routinely included in many chemosensory clinical test batteries to supplement bilateral tests (e.g., Cain et al., 1988; Hummel et al., 1997). Surprisingly, however, the results of unilateral testing in patients with chemosensory complaints have not been extensively reported. Thus, it is unclear how useful these additional measures are in characterizing individual patients.

A …

Consanguineous Marriage Resulting In Homozygous Occurrence Of X-Linked Retinoschisis In Girls, Azam Ali, Agha Hassan Feroze, Zulfiqar H. Rizvi, Tausif- Ur -Rehman

Section of Ophthalmology

Purpose: To investigate a family afflicted with X-linked retinoschisis and to determine the pedigree leading to such an occurrence.Design: Observational case series.
Methods: Visual acuities were measured at The Aga Khan University Hospital Ophthalmology clinic. Slit-lamp examination, direct and indirect ophthalmoscopies were performed on each of the seven members of this family. The pedigree was established by appropriate questioning about the rest of their family.
Results: The pedigree revealed the homozygosity of the four daughters for the XLRS mutations borne out of the consanguineous marriage between an affected father and a carrier mother.
Conclusions: This is the first report showing …

Vegf164-Mediated Inflammation Is Required For Pathological, But Not Physiological, Ischemia-Induced Retinal Neovascularization, Susumu Ishida, Tomohiko Usui, Kenji Yamashiro, Yuichi Kaji, Shiro Amano, Yuichiro Ogura, Tetsuo Hida, Yoshihisa Oguchi, Jayakrishna Ambati, Joan W. Miller, Evangelos S. Gragoudas, Yin-Shan Ng, Patricia A. D'Amore, David T. Shima, Anthony P. Adamis

Ophthalmology and Visual Science Faculty Publications

Hypoxia-induced VEGF governs both physiological retinal vascular development and pathological retinal neovascularization. In the current paper, the mechanisms of physiological and pathological neovascularization are compared and contrasted. During pathological neovascularization, both the absolute and relative expression levels for VEGF₁₆₄ increased to a greater degree than during physiological neovascularization. Furthermore, extensive leukocyte adhesion was observed at the leading edge of pathological, but not physiological, neovascularization. When a VEGF₁₆₄-specific neutralizing aptamer was administered, it potently suppressed the leukocyte adhesion and pathological neovascularization, whereas it had little or no effect on physiological neovascularization. In parallel experiments, genetically altered VEGF_{164 …}

Age, Gender, Biometry, Refractive Error, And The Anterior Chamber Angle Among Alaskan Eskimos, Robert Wojciechowski, Nathan Congdon, William Anninger, Aimee Teo Broman

Dartmouth Scholarship

The prevalence of angle-closure glaucoma (ACG) is greater for Eskimos/Inuit than it is for any other ethnic group in the world. Although it has been suggested that this prevalence may be due to a population tendency toward shallower anterior chamber angles, available evidence for other populations such as Chinese with high rates of ACG has not consistently demonstrated such a tendency.

The Role And Regulation Of Heat Shock Protein 27 In Retinal Ischemic Preconditioning, Norris Andrew Whitlock

MUSC Theses and Dissertations

Introduction: Vision loss resulting from retinal ischemia is associated with several systemic and ocular diseases. In the retina, ischemia is thought to lead to neuronal cell death by initiating a series of events that include oxidative stress, glutamate excitotoxicity, and intracellular Ca2+ overload. Attempts to prevent ischemic retinal degeneration have included the use of NMDA receptor antagonists, Ca2+ channel blockers, and antioxidants. These treatments have had limited success due to incomplete retinal protection and development of adverse side-effects. This has caused researchers to look toward endogenous protective mechanisms, such as ischemic preconditioning (IPC) in order to identify new strategies to …

Structure And Functional Effects Of Age-Related Posttranslational Modifications Of Aquaporin 0 In The Normal Human Lens, Lauren Elizabeth Smith-Ball

MUSC Theses and Dissertations

Aquaporin 0 (AQP0, MIP), a water channel protein found in the ocular lens fiber cells, has been proposed to maintain osmotic homeostasis by contributing to an internal circulatory system within the avascular lens. The formation of cataracts in patients with mutations in the AQP0 gene and in heterozygous AQP0 deficient mice suggests that AQP0 is necessary for establishing and preserving lens transparency. Previous structural characterization of AQP0 revealed that the C-terminus, a putative regulatory domain, is subject to many age-related posttranslational modifications. The goal of the present study was to map the spatial distribution of posttranslationally modified forms of AQP0 …

Thalidomide Prevents Donor Corneal Graft Neovascularization In An Alkali Burn Model Of Corneal Angiogenesis, A. Abbas, Aga Hassan Feroze, G. F. Hyman, B. Khan

Section of Ophthalmology

Objective: Thalidomide is a potent inhibitor of angiogenesis. We evaluated the effects of Thalidomide on corneal angiogenesis and on tissue survival of grafts in rabbit eyes with pre-existing neovascularization secondary to alkali burn.
Methods: Sixteen rabbits received alkali burns to one cornea. One month post-injury, assessments of corneal neovascularization were performed followed by corneal transplantation. Four rabbits received oral Thalidomide and ten got placebo (powdered sugar) for thirty days. Total corneal neovascularization (NV), clock hours (CH) involved in (NV), longest (NV) pedicle length (NVP) and the duration of time required for NV to develop were assessed.
Results: Thalidomide significantly decreased …

Macular Hemorrhage Secondary To Increased Intrathoracic Pressure And Difficult Intubation, A Abbas, G Hyman

Section of Ophthalmology

No abstract provided.

Polymerase Chain Reaction: An Emerging Tool For Research In Pharmacology, Rishi Sharma, Manjeet Singh, Ajay Sharma

Pharmacy Faculty Articles and Research

Polymerase chain reaction (PCR) is a technique that can amplify a specific DNA segment in vitro using two site specific primers that hybridise to opposite DNA strands. The method produces large amounts of specific DNA from a complex DNA template in a single enzymatic reaction within a matter of hours. Reaction mixture contains a double helix DNA, two target specific primers, dNTPs, a DNA polymerase and a Mg2+ containing buffer. PCR is carried out in three distinct steps i.e. denaturation step, annealing step and extension step, which are repeated many times. The efficiency of PCR is measured in terms of …

Multilamellar Bodies As Potential Scattering Particles In Human Age-Related Nuclear Cataracts, K. O. Gilliland, C. D. Freel, C. W. Lane, W. C. Fowler, M. J. Costello

Osteopathic Medicine, Jerry M. Wallace School of

No abstract provided.

Means To Achieve Sustained Release Of Synergistic Drugs By Conjugation, Paul Ashton, Peter A. Crooks, Tadeusz Cynkowski, Grazyna Cynkowska, Hone Guo

Ophthalmology and Visual Science Faculty Patents

A codrug composition of at least two drug compounds covalently linked to one another via a labile bond to form a single codrug composition, or ionically linked to one another to form a single workings composition, and methods of use of the codrug for the treatment of various medical conditions. The codrug may be administered by itself or in the form of a bioerodible or nonbioerodible substance.

Role Of KAtp Channels In Reduced Antinociceptive Effect Of Morphine In Streptozotocin-Induced Diabetic Mice, Vivek Sood, Ajay Sharma, Manjeet Singh

Pharmacy Faculty Articles and Research

The nociceptive effect was measured using withdrawal latency in tail flick test in mice rendered diabetic by administering streptozotocin (200 mg/kg, i.p.). The antinociceptive effect of morphine (4 and 8 mg/kg, s.c.) and cromakalim, a KATP channel opener, (0.3, 1 and 2 micrograms, i.c.v.) was significantly reduced in diabetic mice. Moreover, co-administration of cromakalim(0.3 microgram) did not alter the reduced antinociceptive effect of morphine(4 mg/kg) in diabetic mice. Spleenectomy in diabetic mice restored the decrease in antinociceptive effect of morphine and cromakalim. Multiple dose treatment with insulin to maintain euglycaemia for 3 days in diabetic mice prevented the decrease in …

Effect Of Actinomycin D And Cycloheximide On Ischemic Preconditioning-Induced Delayed Cardioprotective Effect In Rats, Devinder Singh, Ajay Sharma, Manjeet Singh

Pharmacy Faculty Articles and Research

The present study was designed to investigate the effect of actinomycin D, a transcription inhibitor, and cycloheximide, a translation inhibitor, on the delayed cardioprotective effect of ischemic preconditioning. Left thoracotomy was performed in anaesthetized rats at 4th/5th intercostal space and polypropylene suture (5-0) was employed to occlude left common coronary artery. Ischemic preconditioning was produced by four episodes of 5 min of coronary artery occlusion followed by 5 min of reperfusion and thoracic cavity was sutured. Left thoracotomy was performed again after 24 hr of ischemic preconditioning and left coronary artery was occluded for 30 min followed by reperfusion for …